Forklift Safety: Forklift Driver Klaus

Forklift Safety

Forklift driver Klaus is a crazy German short film about forklift safety. The video follows Klaus, a newly licensed forklift driver, at his first day on the job as he blunders through some of the most common forklift safety scenarios. Each safety “don’t” Klaus encounters is more ridiculous and gory than the last, making this 10 minute safety tutorial somehow morbidly hilarious. You will be captivated through the end of the short film, as a beheaded Klaus drives off into the sunset with two fellow coworkers who have been impaled by the forks of the lift truck with the theme song “Happyland” pleasantly playing in the background.

 

forklift safety forklift driver klaus | Intella liftparts

 

Forklift driver Klaus was released in 2000 and had a budget of 90,000. The video is narrated by Egon Hoegen, who is well known in Germany for being the voice of a series of videos covering traffic safety in the ’60s. It can be viewed on the official website (http://www.staplerfahrerklaus.de) in German and English, or you can find it on YouTube with English subtitles where it has been viewed over 1.3 million times.

forklift driver klaus

This popular video may not be an official safety tutorial, but it is often used to keep things light. Although we recognize that forklift safety is a very important, serious subject, the video definitely gets the point across as it covers the most common dangers of unsafe forklift operation in a very unconventional manner.

 

Intella Liftparts carries a complete line of forklift safety items.  Our most popular safety item is our BlueSpot(R) safety light projects a blue spot behind the forklift so pedestrians see forklifts before it’s too late.

 

The SIS forklift radar system alerts forklift drivers of objects behind the forklift.  It’s an added layer of protection to help drivers avoid both people and objects.

 

The most common and most effective forklift safety device is the plain old forklift horn.  OSHA requires forklifts to have horns and they’re very simple to replace in case your forklift horn is broken.  We’ve got a huge selection of horns that fit most brands of forklifts.

 

Intella Liftparts is your source for a variety of forklift safety devices!

 

 

 


Post by Intella Liftparts

HISTORY OF THE FORKLIFT

Learn more about different types of forklift trucks.

History of the Forklift

The fork truck, which later evolved into the forklift, has been in use for over 80 years. No one is quite certain who first invented the fork truck, but the Clark Company is usually credited with inventing it in 1917. This gasoline powered prototype device quickly caught on, and today, there are more than a million forklifts in use in warehouses across the world. But these original fork trucks were quite different from what warehouse workers are using today. Many of the original forklift parts have been upgraded or eliminated as technology has advanced through the history of the forklift.

 

HISTORY OF THE FORK TRUCK

 

The Earliest Fork Trucks

 

The earliest type of fork trucks was the hand truck. It used two wheels and was very similar to today’s dollies. This device used cast iron wheels and wrought iron axles. Their main advantage was that they allowed heavy loads to be moved without beinHistory of the Forkliftg picked up and placed on a four-wheeled handcart. Dock workers no longer risked hurting their backs lifting these types of objects.

 

In 1887, one of the earliest types of fork trucks was built. It could lift its loaded platform a few inches off the ground, but it was very weak and wasn’t widely available. A steel version of this type of lift truck appeared in 1909. It becaHistory of the Forkliftme commercially available. However, it wasn’t a proper lift truck.

 

That appeared in 1917 when Clark introduced what they called the Tructractor, the first type of seated counterbalanced vehicle for use in warehouses and factories. Clark originally had no plan on manufacturing these vehicles for others to use—they simply saw a need for the Tructractor in their axle plant. However, when visitors to the plant saw it, they asked to buy the vehicles, and Clark began mass producing them. While it was a basic design, and it certainly influenced forklift technology.

 

Making Fork Trucks More Powerful

Fork trucks quickly began changing and becoming more powerful. In 1920, hydraulic forklift parts were added to the vehicles to make lifting loads easier. Electronics were slowly incorporated into fork trucks, especially those that made use of small mounted cranes to lift loads onto the truck bed. Early fork trucks were fairly slow also, but over time more powerful engines were added to give them a little more speed and hauling power.

forklift history

The Addition of the Vertical Lifting Cantilever

 

History of the Forklift

The first vertical lifting cantilever, or mast, was introduced in 1923. Engineers at Yale University created an electric truck that could lift the forks and their load up via the mast. It made use of a ratchet and pinion system to do this. This is often considered to be the first true forklift, and it revolutionized the way things were stored. However, there was still one major issue that prevented the Yale forklift from becoming incredibly popular: some pallets were either too large or too small for it to pick up.

That problem was solved during the late 1930s, when pallet size was standardized. This, in turn, led to the standardization of forklift fork size, length, and spacing. Now the forklift went mainstream. World War II saw the vehicle become even more in-demand since the military needed a fast, efficient way of moving large quantities of items onto ships and cargo planes. The forklift was the answer.

 

Advancements in Forklift Technology

Since then, there have been a number of advances and changes in forklift technology. In order to protect operators, backrests were added to the masts to help keep loads from falling backwards. A cage was also placed around the driver to add more protection. Forklifts are better balanced today, which has also helped reduce the number of forklift accidents.

One of the biggest advancements has been in forklift power sources. While early lift trucks and forklifts ran exclusively on gasoline, today, many are electric vehicles. Forklift batteries can now provide enough power to run for hours, while the electric forklift motor is strong enough to lift very heavy loads. These forklifts are much safer to use in enclosed areas because they give off no emissions. They’re much more environmentally friendly, which is a must for companies trying to reduce their carbon footprints.

 

Forklifts have also integrated computer systems into the operator’s seat. These systems tie into the warehouse’s or company’s inventory control system and allow operators to scan barcodes or read RFID chips. This has made inventory much easier to manage, resulting in a much more efficient system in which very few pallets are lost or placed in the wrong area.

 

But that’s not all. Changes in ergonomics have made it more comfortable for forklift operators to work for longer periods of time. Smaller body designs have resulted in forklifts that no longer need a large amount of space to operate, which means storage facilities can have narrow aisles, which in turn means they can store more pallets. A number of forklift manufacturers even offer customization, letting businesses chose which options they need for their forklifts.

 

As technology changes, forklifts will continue to adapt, becoming more powerful, safer, and more efficient.

 

 


Post by Intella Liftparts

FORKLIFT BATTERY MAINTENANCE

Forklift Battery Maintenance

Forklifts may use several different types of batteries. Electric forklifts require the battery to operate, while gas powered forklifts need a battery to start. Over time, these batteries will run down. Electric forklifts will need to be charged periodically, while other types of forklifts will need the battery completely replaced when it runs down. Replacing these batteries is done in much the same manner as a battery on an automobile, so we will focus more on maintaining batteries in electric forklifts.

 

 

What Makes Up the Battery?

An electric forklift battery is made up of five different parts. Those who work on an electrical forklift should know these parts to avoid getting shocked or, worse, causing the battery to explode.

 

  1. 1.  The battery cells – the battery is divided into different cells, each of which contains a set of positive and negative plates. The plate at each end of the cell is negatively charged, and plates alternate throughout the cell. The number of cells determines how many volts the battery produces.
  2. 2.  Separators – each of the positive and negative plates is separated by a separator, which provides the insulation.
  3. 3.  The battery tray – this is the container that holds the battery cells. It’s usually made from steel.
  4. 4.  Electrolyte solution – everything inside each cell is submerged in an electrolyte solution made of sulfuric acid.
  5. 5.  Element – the top of each cell features an element made up of one positive and one negative terminal. The positive plates are all connected to the positive terminal, while the negative plates connect to the negative terminal.

 

Forklift Battery Maintenance

 

 

How Can you Select the Best Battery for your Forklift?

One factor in deciding on the best battery for your forklift is to look at its size. Larger forklifts that are rated for lifting larger loads are going to need bigger batteries because they will require more power. Smaller forklifts won’t have as much weight to move because the frames are usually lighter, plus they’re not rated for lifting really heavy loads. Another very important factor when selecting proper battery size for your forklift is weight. In an effort to save money, it may be tempting to purchase a smaller battery. Minimum battery weight is listed on the data tag located on your forklift. It is very important to fit a battery that meets these weight requirements. The battery is factored into the counterweight and crucial to the lifting capacity and safety of the forklift. Make certain you get the correct size battery for your forklift.

 

Before purchasing a new battery it would be wise to have the battery inspected by a battery technician. Often these batteries can be repaired. It may be a matter of replacing a cell or two. It may just need an acid adjustment. These remedies to not make your battery new again but can in some cases extend the life by a few years.

 

Be careful when buying off-brand batteries. Yes, they may work in your forklift, but they may also be cheaper for a reason—many off-brand batteries are of a lesser quality and will not last as long as the more expensive brand names. Look for product reviews before you make a purchase.

forklift battery

 

Tips on Charging the Battery

Maintaining a proper charge on your forklift battery is important. If the battery isn’t properly charged, it will run down much more quickly, and then you’ll end up spending more money on replacement batteries than you should. Here are a few quick tips on charging your batteries to make certain you get the most out of them.

 

 

  • •  Recharge your battery when it has about 20 percent power left, not before. Recharging a battery when it has more power may damage the battery and shorten its life.
  • •  You don’t have to charge a battery daily—if it’s not run down, don’t charge it. Most forklift batteries are designed for a certain number of charge cycles (1,500 or more). If the battery doesn’t need to be charged, don’t waste one of these cycles.
  • •  To make sure the battery is performing at its best, use the equalize, weekend, or weekly charge setting (the term varies from brand to brand) once every five to ten recharge cycles. This will help ensure longer battery life. However, don’t use this setting too often or you may damage the battery. You may want to keep a log of when these special charge cycles are done to help with this.
  • •  You’ll also want to keep a log of when water was added to the battery. New batteries will need water added to them once every ten charges for the first couple of years in use. After that, or if you’re using a reconditioned battery, you may need to add water to it after every five charges.
  • •  Add water after the charging cycle, never at the beginning of a cycle.
  • •  Don’t interrupt a charge cycle. Doing so will waste one of your charge cycles, plus it can damage the battery.
  • •  If a battery does run completely down, be sure to recharge it as soon as possible. Don’t let it sit for a long period of time.

 

Steps on Replacing the Battery

On average, a battery for an electric forklift will last around five years, less if it’s used and recharged a lot. Under ideal conditions a well maintained low usage battery can last as long as 10-12 years. Fortunately, these batteries are fairly easy to find, and most are reasonably priced.

There are a number of signs that your forklift battery is about to expire. Here are a few of the most common:

 

  • •  It doesn’t hold a charge for long
  • •  It needs recharged several times during the day
  • •  The battery case starts to show corrosion buildup
  • •  The battery begins to smell
  • •  The battery begins to smoke while in use or when charging—replace this battery immediately!

 

Replacing a forklift battery is not as simple as replacing other batteries. The first issue is that the battery can weigh several thousand pounds. It’s going to take another forklift to move it. It can also be very dangerous as batteries carry high amperage that can be deadly if not handled correctly. In many cases, it’s easiest to simply have a battery technician do the installation. These professionals have been trained in forklift battery replacement and can handle everything.

However, if you’re going to do the replacement yourself, you should first make certain that you keep the top of the battery clear of all metal objects. Otherwise, the battery could short circuit and explode. You should remove any jewelry you’re wearing such as a wedding ring—even that small bit of metal can cause an arc. Even keep the connector cables away until you’re ready to connect it. Keep them out of the way, and make sure they’re not going to get caught under the battery.

Now move the new battery under the hoist using a second forklift. Make certain the hoist hooks are securely connected to the battery’s lifting hole. Lift the battery up, carefully move it into position, and then lower it into the forklift. Connect the connector cables and power up the forklift to make certain it works.


Post by Intella Liftparts

REPLACING BLOWN FORKLIFT FUSES

Replacing forklift fuses

 

My electric forklift doesn’t run!   Could it be a forklift fuse? Often this is the case. Let’s look at how to check your forklift fuses.

Step one:

Disconnect battery from forklift and discharge capacitor.

 

REPLACING BLOWN FUSES ON ELECTRIC FORKLIFTS

 

Remove covers to gain access to fuse panel.   Control fuses are sometimes found under the dash.  These will be Glass tube or blade type fuses.

 

replacing fusesForklift Fuse Control Panel

 

Most electric forklift fuses are found in the area of the contactor or control panel. You will also find larger power fuses (35 to 500 amps).  Below is a picture of fuses in a standup Yale ESC40-FA forklift.  You’ll see the fuses this truck uses are ANN80 fuses.

 

Electric Forklift Fuses

 

 

Here are photos of other types of forklift fuses you may encounter on electric forklifts.

 

 

forklift fuseforklift flat fuse80a forklift use

 

 

Visually inspect forklift fuses looking for signs of heat (melted or discolored connections). If you have the glass fuses or fuses with a window you may be able to see an open or damaged fuse.

 

If you have access to a multi-meter (VOM), there are multiple methods to test your forklift fuses. You can test using continuity mode or resistance mode. You must remove fuse from circuit in order to properly test using this method. You are looking for no resistance.

 

In rare cases a fuse may pass the visual test and continuity test but may still be the faulty. Forklift fuses can sometimes have enough capacity to show continuity but will not carry current loads. The best method to test a fuse if you suspect this to be the case is to check for voltage. This can be dangerous if proper care is not taken. Be sure to block forklift so that it cannot move if drive circuit is energized unexpectedly. You must first plug in the battery. Always use care when working with live circuits. Locate the common negative terminal. Easily found by following the negative cable from the battery connector the first connection point on the forklift. Keep in mind that electric forklifts are not chassis grounded. Connect your negative lead from your VOM to this terminal. Now probe your fuses on both the supply side and the load side. You should get a reading that closely matches the voltage of your forklift battery at both points. For some control fuses you may need to turn the key on, sit on seat and release park brake in order to energize the circuit prior to testing. If you get the proper voltage reading on both sides of the fuse, the fuse is probably not the cause of the problem.

 

If you want to test the fuse even further you can test it under load. Be careful this can be dangerous if not done properly. If you do not feel comfortable please do not proceed. Fuses are inexpensive. Replace the fuse if you still suspect it is causing problem. If you work carefully, perform proper blocking methods, and be sure to have a clear working area you can energize the circuit and check voltage on load side of fuse. If voltage goes away when circuit is loaded, replace fuse.

 

Always replace fuses with the proper type, value and size. Improper fuses can cause extensive damage to other forklift components.

 

Keep in mind that if you find a blown fuse you should determine the cause to prevent further failures. Often power fuses are damaged from overloading such as pushing loaded pallets along the floor. If this is the case your forklift is working properly and some training is in order for your operator.  If the operator is not the cause you should look for a shorted circuit or component that has caused the failure.  See “How to check for shorted or open circuits

 

Once all connections are made replace covers and reconnect battery. Test operation.

 

Congratulations! You have successfully repaired your forklift.


Post by Intella Liftparts

SHORTED OR OPEN FORKLIFT CIRCUITS

Forklift Circuits

Are you having trouble understanding the difference between an open electrical forklift circuits and a shorted forklift circuits? In this article I will try to explain the different types of electrical forklift faults and how to test your forklift circuits. First let’s cover some terms we will be using in this article.

 

  • Open Circuits: Open forklift circuits are by far the most common of electrical faults. Open circuits are broken wires, open or corroded connectors, defective switches, etc. Anything that forms resistance so that current can’t pass through it will become an open circuit. Broken wires can be caused by repetitive bending of wires such as on a seat harness, or chafing of the wire against another component. Switches can become mechanically broken or corroded.

 

  • Shorted Circuits: A short circuit occurs when current flows directly to common instead of through a load. Because a path directly to common has much less resistance than a load, electricity will not only choose this path (electricity always follows the path of least resistance), but it will do so with increased current, usually resulting in a blown fuse.

 

  • Grounded Circuits: These are circuits that have become grounded, connected to the frame or chassis. A wire that has been rubbed through and lies against the frame is one example.

 

  • Source Voltage: The system voltage available to the circuit measured at the battery. Common voltages are 12v, 24v, 36v, and 48v ± 2v.

 

  • Common or COM: Electric powered forklifts do not use a chassis grounded circuit common in the automotive industry. Forklifts use an insulated circuit consisting of wires, cables, terminals and connections that complete circuit to the common side of the power source. This can be the positive or negative side of the circuit although negative is the most common in modern lift trucks. This is an important concept to understand when diagnosing electrical circuits in your electric powered forklift.

 

  • Fusible Link: A wire or cable designed to melt open when subject to high current in a circuit opening the circuit to prevent further damage. Like a fuse these need to be replaced when found blown open.

 

Here are some of the symbols used in the diagrams below:

 

Shorted or Open Circuits

 

When troubleshooting electrical circuits, we encounter three types of faults. Types of faults are open, shorted, grounded or a variation of these.

 

Often, technicians confuse open circuits with short circuits. Remember, an open circuit is one where the circuit has actually had current flow stopped by extremely high resistance. A short circuit is too much current flow due to very low resistance.

 

 

Open Forklift Circuits                         

Open Circuits A voltage drop test is the best method for testing open circuits. The quickest way to narrow down your search is to look for available voltage.

 

Using the appropriate wiring diagram, identify some easily accessible areas to measure for available voltage. With one probe on the wire in the circuit, place the second probe on the common post.

 

If you measure source voltage that means that you have an open circuit between your meters leads. Move the positive lead to another test location closer to the ground point while keeping the other lead on the COM.

 

As you move down the circuit you will eventually find a spot where the meter will read less than 0.1 volts. When this happens you know that the voltage is being dropped somewhere between your last test point and COM. Using your wiring schematic as a guide, you can determine what component, wire or connection needs further inspection or testing.

 

 

Short Forklift Circuits

Short CircuitsAlthough not as common as open circuits, short circuits do occur and can be troublesome to diagnose.

 

A short circuit will blow a fuse, melt a fusible link, or cause a circuit breaker to trip.

 

Diagnosing a short circuit involves replacing one of these circuit protection devices with something that can handle the excessive current flowing in the circuit. Many different forms of “short finders” are available on the commercial market. If you don’t own one of these you can make a usable tool by wiring a sealed beam headlight bulb with two leads with alligator clips.

 

Wiring diagrams or schematics differ between manufacturers. Some diagrams will provide a chart showing each fuse circuit down the left hand side, with each system circuit across the top. Find the fuse that keeps blowing and move across the page from left to right noting each system circuit that you come across. By disconnecting one system at a time you can narrow down the source of the short.

 

Other wiring diagrams will only provide a list of system circuits by fuse, or an actual wiring diagram of the fuse box. If you only have a wiring diagram to go by, you will have to be diligent in making sure you don’t miss a system circuit connected to a particular fuse.

 

Back to finding a short circuit: Connect the headlight bulb into the fuse holder in place of the blown fuse. When you turn the circuit on, the headlight should light as it consumes the excess current. Next, identify what components are on the circuit by using the wiring diagram.

 

Begin by disconnecting each component, one at a time, until the headlight goes out. The component you disconnected to make the headlight go out is the circuit you need to investigate.

To find the actual short, with the headlight bulb still in the circuit, and the component plugged in, disconnect the circuit at various locations until you find a location where the bulb does not go out.

 

You have now narrowed your trouble spot to somewhere between the last connector you disconnected (the one that DID NOT make the bulb go out) and the power source. Now a visual inspection or a continuity test will help you make a final diagnosis.

short circuited

 

Grounded Circuit

Grounded CircuitA grounded circuit where a portion of the circuit becomes connected to the frame does not create an immediate problem until a second ground is created. This creates a short between the two forklift circuits involved. A common mistake in forklift wiring is to install an accessory such as a light or radio and connect the negative to the frame. This can cause all sorts of problems. Never connect or “ground” any device to the frame or chassis.

 

A headlight connected to either positive or negative side of your power source and the chassis should never light. If it does you should locate the source whether pinched, chaffed or improper wiring it needs to be corrected or risk damage to expensive control circuitry.

 

Hopefully this gives you a better understanding of forklift circuit problems that will help you diagnose your next forklift dilemma.


Post by Intella Liftparts

ELECTRIC FORKLIFT DIAGNOSTICS

ELECTRIC FORKLIFT DIAGNOSTICS

So your forklift won’t move, where do you start?  Here are some basics in understanding electric forklift diagnostics.  Whether your forklift is electric powered or engine powered the problem could be your forklift electrical system. In this article I will explain the basics of electrical forklift diagnostics.

 

Because electricity is not visible, it is not easy to diagnose. Compounding the problem is that electrical schematics and diagrams can be confusing. I will try to equip you with the tools needed for proper diagnosis. A technician has to rely on those tools to show where electricity is, or where it isn’t, and then draw accurate conclusions from that knowledge.

 

If you can learn to “think” like electricity and skillfully use your multi-meter. With an understanding of some basic electrical principles you can then apply them to testing electrical systems.

 

Have you ever witnessed a technician spending time looking at wiring diagrams or drawing sketches on a piece of paper. He was actually diagnosing the problem at hand. A big part of electrical forklift diagnosis is done at the bench before ever lifting a wrench. A multi-meter (VOM) is the second most useful tool in your arsenal after your brain.

 

UNDERSTANDING ELECTRIC FORKLIFT DIAGNOSTICS

 

Computer controlled systems offer another complexity to the way electricity works. It is easy for technicians to replace a control board, often because they don’t understand what it does or how it works. This often results in unnecessary expense and can also cause the new part to be damaged because the original problem was not corrected.

 

By understanding what a control board needs in order to function properly and then ensuring that it has everything it needs to do its job, a technician can successfully determine whether the board needs to be replaced.

 

OK, so let’s get started. A simple understanding of electricity and basic terms is in order.

electric forklift diagnosis

What is VOLTAGE?

Voltage can be thought of as electrical pressure. Voltage is the force that pushes electrons along an electrical conductor. The measurement for voltage is called the volt. There are two types of voltage: alternating current and direct current. In forklift circuits we are use both direct current and alternating current.

 

Direct current voltage (DC voltage) is voltage that is applied in one direction all of the time. Most forklifts use direct current to get their jobs done. Industrial forklift batteries or automotive type batteries supply direct current to the electrical circuits.

 

Alternating current voltage (AC voltage) is voltage that is applied in both directions in an alternating fashion. This is similar to the electricity found in the electrical outlet of your house wiring.

 

Some modern forklifts use AC powered motors as they require less maintenance and can be more efficient than their DC counterparts.

 

What is CURRENT?

Where voltage is the driving force in an electrical circuit, current or amperage is the measurement of how much electricity (electrons) is flowing in a circuit.

 

We measure current in amperes (amps). Current is the quantity of electrons passing a single point at any given time. Current can be measured in both AC and DC circuits.

 

What is RESISTANCE?

Resistance is the opposition of flow in an electrical system. This is sometimes built into the circuit for various functions. All loads create resistance that is normal in a forklift circuit. Resistance can also be caused by lose connections, faulty components and faulty wiring. Understanding resistance can be a key component in understanding how to diagnose electrical circuits.

 

Resistance is measured in OHMS Ω.

 

How can we see these different parts of electricity? Using a VOM we can measure the existence of voltage, amperage, and resistance.

 

To measure voltage; place the black lead of your meter in the com jack of your meter and place the red lead in the V jack. Now adjust the meter to AC or DC depending on the circuit you are testing. Set the meter on auto range. If your meter does not have this functionality, you should set the meter to the highest voltage that you expect to be reading.

 

There are two types of voltage measurements that are useful in forklift diagnosis: available voltage and voltage drop.

 

AVAILABLE VOLTAGE

Available voltage is voltage that is present at any given point in the circuit. You can measure available voltage by placing the red meter lead at some point in the circuit (switch contact, fuse, connector, etc.) and the black meter lead on a common terminal. This test will tell you how much voltage, or electrical pressure, is present to do some work at a given point in the circuit.

 

The available voltage test is good for determining if you have voltage present, but it does not do much in the way of diagnosing what is wrong with the circuit.

 

Available voltage is a good test to use when you want to see whether voltage is present at a point in the circuit or not. You can think of the available voltage test as a “go, no go” type of test.

 

Do not use the available voltage test to determine whether a circuit is functioning properly or not. There may be voltage present at a point in the circuit, but that does not mean that the circuit has what it needs to work.

 

VOLTAGE DROP

The second voltage test while performing electric forklift diagnostics, and by far the most useful, is called a voltage drop test.

 

We say that voltage is “dropped” when some form of load uses all, or a portion of, the voltage available.

 

Loads come in the form of motors, solenoids, contactors, lights, etc. Corrosion, open circuits and damaged contacts can also be considered loads on the system as they can cause voltage drop also. When a load of this type “uses up” or drops voltage, then it may not leave enough available voltage to the rest of the circuit for the circuit to work properly. A voltage drop test will help you to isolate where voltage is being dropped, or used up.

 

Unlike resistance measurements where the circuit is not turned on, a voltage drop test is performed with the circuit working or turned on.

 

To perform a voltage drop test you must place the meter leads at two points within the circuit. Remember, during the voltage available test we place the leads at one point in the circuit and the other to common. In the voltage drop test, both meter leads will be placed in the circuit.

 

With the meter leads placed in the circuit, you are now measuring how much electrical pressure, or voltage, is present between the meter leads. If you measure any voltage at all on the meter display, then there must be some sort of load between the meter leads.

 

Your next job is to determine whether the load that is represented on the meter display is a load that is supposed to be there, or whether it is a load that may be harmful to the circuit. Remembering a few simple rules will allow you to determine if the voltage drop you are measuring is “normal” or not.

 

A meter reading of less than 0.1 volts represents a wire, or switch that is operating normally.

 

A meter reading of full source voltage represents all of the available voltage being dropped. This could be due to an open wire, or it may be a “normal” load that happens to be the only load in the circuit.

CURRENT

The third measurement that can be useful in electric forklift diagnostics is the measurement of current, or of how many electrons are flowing. Current is measured in amperes, or amps for short. Like the voltage drop test, an advantage of measuring current is that the circuit will be performing its function, making this a “real world” test.

 

The technician must first determine what current or amperage draw is normal for the component or circuit he or she is working on. Current specifications for even common circuits can be hard to come by. If specifications are not known they can sometimes be found printed on the component as on a coil or motor. You can also compare to a known good component.

 

The second drawback to testing current during electric forklift diagnostics is in that the meter must be installed in series with the circuit you are testing. Since current measurements are actually measuring how many electrons are flowing in the circuit, all of the electrons in the circuit must pass through the meter. This means that the meter must become part of the circuit. An ammeter must be installed in series with the circuit, at a location where the maximum current within the circuit will flow through the meter. This involves opening the circuit up and connecting the meter leads in series with the circuit.

 

There are a number of good locations for opening up a circuit up to install the meter while performing electric forklift diagnostics, with the most popular, and often the easiest, being at a circuit fuse. This is done by removing the fuse and installing the meter leads on either side of the fuse connectors.

 

The third drawback to using current as a diagnostic tool is that you may not know how much current is flowing before you install your meter. The current flowing is often more than what your meter can handle. Although a quality meter is fused, often these fuses will blow when trying to measure current because the circuit being tested uses higher current than what your meter is designed for.

 

To get around these last two drawbacks, technicians will use an “amp clamp” or an inductive ammeter for electric forklift diagnostics. This device uses the electromagnetic field that forms when electricity flows through a conductor in order to determine how much current is flowing in a circuit.

 

Amp clamps have two significant advantages: firstly the circuit does not have to be opened up to install the ammeter, and secondly the amount of current flowing in the circuit cannot damage the meter. The disadvantage is that you must purchase an amp clamp that measures the range of current you expect to find. It is not possible to purchase a single clamp that will measure all current ranges.

 

With these basics, a good Multi-meter, and a wiring diagram or schematic the technician can navigate circuits to determine where voltages or currents exist in there correct specifications. Before replacing components a good mechanic will assure that all necessary wiring and circuitry is in place that could cause component to fail.


Post by Intella Liftparts

Electric forklift service tips and tricks

Need some tips on repairing electric forklifts?  Check out this tip from a seasoned mechanic!

 

When performing any tests or repairs on forklift electrical systems, always disconnect battery and discharge the capacitors.

The below photo shows a few different styles of battery connectors and how to disconnect them from a forklift.

Disconnecting forklift battery connector
Disconnecting forklift battery connector

After disconnecting the battery connector, a simple method is to discharge the capacitor is to press and hold the horn button until capacitor is discharged.

 

Forklift horn discharges capacitor

 

NOTE:  This method does not work on all forklifts. A better method is to use a resistor or a VOM set to a high voltage scale.

A 220 ohm resistor will work well if placed across the capacitor leads. Keeping fingers away from leads hold it for a couple of seconds to insure it is fully discharged. To make sure the capacitor is discharged, measure the voltage with your VOM. You can also use your VOM to discharge the capacitors. This works very slowly due to the high internal resistance, this is slow but very safe you will be sure the capacitor is fully discharged when the meter reads zero volts. Don’t forget to disconnect the battery first!

 

Forklift capacitor

Never replace forklift fuses with other than the proper value fuse. If a fuse continues to blow that means there is a short or partially shorted circuit in the system.

electric forklift service


Post by Intella Liftparts