Tech Tips

It is important to ensure that when performing maintenance or a repair procedure, any hoses or electrical cables that may have been replaced or moved be returned to their original positions. As the equipment is operated, the hoses and cables flex and bend, and without proper support, this action causes a straining and pulling tension on them. The use of support clamps, cable ties, along with using the correct fittings and correct hose and cable lengths minimizes or eliminates this tension to help ensure a long life. When replacing a hose or cable, make sure to use the correct parts for the model and serial number of the machine you are repairing, and use all of the support clamps and cable ties as the original configuration.

An example of an incorrect hose replacement is found in figure 1 below. The two hydraulic hoses that are loose on the right side are under tension and are being pulled up against the edge of the equipment structure. Both hoses had been replaced but were not routed through the support clamps which are just out of sight under the frame. Not using the support clamp has allowed the hoses to be pulled against the frame, resulting in damage. The bundle of hoses on the left are routed in a gentle arc and properly supported by the clamps under the frame and are not under any tension as the equipment is operated.

Figure 2 shows the same two hoses after being installed into the support clamp just under the frame. You will notice that the hoses no longer contact the frame and have no possibility of rubbing and becoming damaged. The clamp holds the hoses away from the frame and relieves the tension that caused the damage. These hoses still require replacement, but you can see how the support clamp would have prevented the damage to the new hoses.

When inspecting equipment, make sure the hoses and cables are properly routed, look for any damage, check the hose and fittings are the correct type and rating, and verify that there is good support to eliminate pulling or tension as the equipment is used.

When replacing a hose make sure the hose and fittings are the same specifications as the manufacturer’s original parts and make sure the length is correct. When replacing an electrical cable make certain the cable is the correct part number for the model and serial number of the equipment you are repairing and the cable is the same length as the original. Always use all of the support clamps and cable ties as the original installation.

TECH TIDBIT

Skyjack has introduced several new models of equipment in the past few years; telescoping and articulating boomlifts and small rough terrain models in both engine and electric powered designs. As with any equipment, it is important for the technicians to take some time with the operator’s manual and familiarize themselves with the newer models operating characteristics. Use the copy of the operator’s manual that must be in every manual box and read through it and operate the unit to get comfortable with how it is supposed to function. When troubleshooting a problem later on the old adage applies ‘you can’t fix it if you don’t know how it’s supposed to work’.

The Skyjack engine powered rough terrain scissorlift and boomlift models can be equipped with a hydraulic generator option to supply AC power to the platform. Some boomlift models can be equipped with a welder package option to power a small welder in the platform.

The generator is controlled by a coil operated valve that routes oil flow to the pump located on the generator pack. The generator rotates and produces an AC voltage that is sent to the AC receptacle on the platform.

If you have a problem, the first thing to check is that the generator is spinning. Check the generator shaft for rotation with the circuit turned on. No rotation may mean the valve is not working or not getting powered. Check for oil flow to the generator pump.

If the generator pump shaft is rotating, check the pump/generator coupling, it can get loose and slip on either shaft. If the coupling is good and the shaft is spinning properly, check the RPM’s of the generator shaft. The generator manufacturers specify a rotation speed of no less than 3600 RPM. This is critical; some generators will have low output at 3550 rpm. Use a photo tachometer to test the shaft rotation speed. If an adjustment is needed, some generator hydraulic circuits will have a flow control valve which can adjust the flow to the generator pump to attain the proper speed. Remember to always check AC output at the generator in case the problem is the wiring to the platform. If you have good voltage, and still no tool operation, check the hertz of the AC signal. Most volt meters have a hertz test selection and in North America the hertz should be 60Hz when read on the meter.

Generator packages from several manufacturers are used on our models and can be slightly different from each other. Always reference the correct manual for the serial number of the unit you are working on to obtain the correct test and adjustment information.

If you have any question regarding your Skyjack product, please contact Skyjack Product Support at 1-800-275-9522 or email service@skyjack.com.

The Skyjack Vertical Mast models SJ12 and SJ16 feature a traversing platform that allows the operator to extend the platform when elevated and safely reach a larger area without repositioning the machine. The platform can also be fully extended into the service position which provides a means of access to the hydraulic/electric compartment in the base to allow a technician to service the unit. For information regarding the proper operation of the platform, see the correct operator’s manual for the serial number of the unit you are operating or servicing.

The following pertains to ANSI/CSA machines. For all other regions, please consult the correct operating and service manuals for the serial number of the unit involved.

The traversing platform is equipped with a service position limit switch that prevents machine operation when the platform is extended fully into the service position. For troubleshooting/testing, the machine is equipped with a diagnostic switch that overrides the service position limit switch and allows the technician to operate the unit with the platform fully extended in the service position.

The diagnostic switch is located on the panel above the pump motor along with the main and ground circuit breakers. The pictorial decal by the switch is shown in Figure 1. Moving the switch and holding it will power the motor controller enable circuit (19B) and allow machine operation.

If you experience a no function/no pump motor situation from both the platform and base controls, first examine the platform service position limit switch. Make sure the deck is completely retracted and the limit switch plunger is not depressed. Check that the area is clean, and the limit switch plunger is operating mechanically. If that does not fix the problem, extend the platform to the service position and access the diagnostic switch and test the unit for function operation.

For answers to technical or other questions regarding your Skyjack aerial work platform or telehandler, please contact Skyjack Product Support at 1-800-275-9522 or email service@skyjack.com.

JULY 11–15, 2016

** REMEMBER THESE DATES! **

During this week, the Technical Support Staff will be involved in our Annual Training Seminar.

Monday July 11th – Thursday July 14th:
ALL ACCESS TO OUR TECHNICAL STAFF WILL BE VERY LIMITED DUE TO TRAINING CLASSES. WE WILL BE TAKING MESSAGES, AND OUR TECHNICIANS WILL BE RETURNING IMPORTANT PHONE CALLS DURING THESE DAYS.

Friday July 15th 2016:
NORMAL ACCESS TO THE SERVICE TECHNICIANS WILL RESUME.

Technical information is always available at www.skyjack.com.

** THE PARTS DEPARTMENT WILL NOT BE AFFECTED **

We appreciate your patience during these few days.
This time allows us to work together to provide the high level of technical support that our customers have come to expect.

THANKS AGAIN!

An often overlooked spot on the Skyjack electric powered scissor lifts is the A.C. interlock connection. It is located at the rear of the battery charger and is labeled as AC Interlock. If the label is missing, look for two 14 GA. wires (one black/one white) leading to a white connector. See figure 1:

The purpose of the interlock circuit is to prevent the unit from being operated while the charger is plugged in. When the charger is connected to an AC power source, the 120V relay (L1CR) inside the charger opens the contacts cutting power from the main circuit breaker on wire 3A to the 05 wire (power to the emergency stop switch) preventing the machine from operating. See figure 2:

White Connector
If you experience total loss of functions, check that the charger is not plugged in, then check the interlock connector. The connector may be loose or corroded causing the power loss. The other cause may be a bad relay in the charger. This relay does not affect charger operation. If necessary, you can bypass the connector by connecting wires 3A and 05 together on the machine side of the connector.

If you encounter this situation or if you have a question regarding your Skyjack product, and need assistance, please contact Skyjack Product Support at 1-800-275-9522 or email service@skyjack.com.

On the rare occasion that a Skyjack product has a problem, the service technician may need information to help troubleshoot and repair the machine. Just call Skyjack Product Support at
1-800-275-9522, and follow the prompts to get to technical support. Skyjack employs field experienced technicians that are able to answer questions and assist with any issue that you may have regarding your Skyjack product.

When you call, please have some information ready so our technicians can assist you accurately and quickly.
Please speak clearly and provide the following:

• Your Name, Company, and location
• Model and Serial number
• Hour meter reading
• An accurate description of the problem

In order for us to provide assistance in troubleshooting a problem, an accurate description of the problem is vital. A good practice is to operate all the functions and note which do not work. Many times, multiple functions that do not work will be related and can be a clue to where the problem exists. Then check the basics; make sure that all wires are connected, all relays are in their bases, the fuel tank has fuel, etc., - before you call. Many problems are solved by finding a loose connection.

As a technician, you are required to be familiarized with the operation of the equipment you work on. Please review the operator’s manual, which is required by ANSI to be in the manual box on every machine at all times.

Basic tools and test equipment are also important to have. A multimeter and hydraulic pressure gauges are essential testing tools. One of the best tools is the service manual for the model and serial number of the unit being repaired. Service manuals are easily accessed on our website www.skyjack.com or available on a USB flash drive – part number 167847 available from our parts department.

When performing an annual inspection, please contact technical support to find out if any service bulletins are open for the serial number of the machine you are inspecting. Completing all the service bulletins is necessary to satisfy the annual inspection.

We at Skyjack Product Support make it our goal to provide you with the best technical support in the industry. One of the keys to both your success and ours is effective communication. Using this information as a guide will help us help you. Please call 1-800-275-9522 or email service@skyjack.com for assistance with your Skyjack product.

When troubleshooting any problem, it is essential that you know how the function works in order to be able to fix it. Outrigger inspection procedures can be found in the applicable operating manual for the serial number of the unit you are working on, as well as the Service Advisory dated September 1, 2010.

We receive many questions relating to the outrigger auto level system on the Rough Terrain Scissor lifts. Simply put, the outrigger auto level system operates in two steps:

• Step 1: The outriggers extend until they first contact the ground and start to lift the frame slightly. The extend limit switches on the outriggers close, telling the auto level module that the outriggers have touched the ground and power to that valve should be shut off.
• Step 2: Once all four outrigger extend limit switches verify that all outriggers are extended and on the ground, the module extends only the necessary outrigger(s) to level the frame.

If you experience one or more outriggers extending too far, the extend limit switch for that outrigger may be sticking or failing. If the outrigger extends too far, the system cannot level the unit. The module will not retract an outrigger to achieve level. The extend limit switches are located at the point where each outrigger leg is slid into the frame.

Finding the problem by testing the extend limit switch inputs to the auto level module is easy. Test at the P2 connector on the module. The extend limit switch wire numbers are 68A, 67A, 66A, and 65A. Wire 68A corresponds to the left rear limit switch. 67A right rear, 66A right front, and 65A left front. Operate the auto level function and as each outrigger closes it’s extend limit switch, you will see input voltage (12V) at that pin position. If you see voltage at the pin and the outrigger does not stop, the module is most likely bad. More specific schematic and outrigger circuit diagrams are available in the correct service manual for the serial number of the unit you are working on. Service manuals are available at www.skyjack.com or using the USB flash drive available from parts department.

If you have any questions regarding the auto level system or any other specifics on your Skyjack product, please contact Skyjack Product Support at 1-800-275-9522 or email service@skyjack.com.

The Skyjack SJIII Compact and Conventional model electric scissor lifts with the MC option and all of the SJ12/SJ16 Vertical Mast models utilize a motor controller to control the function speeds. The motor controller controls the rotation speed of the pump motor which, through the pump rotation speed, results in precise control of the function speed.

The motor controller is simple in operation. It has 2 inputs: a control enable input that tells the controller it is OK to operate, and a speed signal input telling the controller how fast to rotate the pump motor. Once the control enable input sees a voltage higher than 12VDC, it allows the controller to monitor the speed input and operate the motor. If the enable input detects a problem (interruption or dropping below 12VDC of the input signal) it will shut down the controller. The speed signal input operates on a voltage between 0 and 5VDC. At 0.2VDC the controller will start applying voltage to the pump motor and increase this voltage until input signal is 3.86VDC which is considered 100 percent. If the speed input exceeds 4.6VDC the controller will shut down.

When troubleshooting, check the connections at the motor controller for loose or corroded terminals. Then check for the enable input, it should be system voltage. Operate the joystick and observe the speed input. It should start at 0VDC and increase as the joystick is moved from neutral staying below 4.6VDC at full joystick travel. If these inputs are correct the problem may be the motor or the controller itself.

More specific information is available in the service manual for the serial number of the unit you are working on. The full manual selection for your Skyjack model is available at www.skyjack.com or using the updateable USB flash drive available from our parts department. Use part number 167847. For technical assistance, please contact Skyjack Product Support at 1-800-275-9522 or email service@skyjack.com.

Skyjack products are designed and tested to ensure correct operation and reliability. In spite of our best efforts, there are occasions when a modification must be made to a piece of equipment after it has been delivered to a customer and placed in service. Service Bulletins are used to communicate required modifications to machinery that is in the field. The scope of Service Bulletins may range from the simple addition of a label to an inspection or a more involved electrical, hydraulic, or structural modification.

Service Bulletins are divided into 2 categories: safety related and non-safety related. A safety related Bulletin addresses issues that impact the safe operation of the equipment. The Bulletin cover page will have the words "SAFETY RELATED" below the Bulletin’s number and title. To ensure the safety of users and operators of the equipment, the instructions in a safety related Service Bulletin are mandatory and must be followed as directed in the Bulletin.

A non-safety related Bulletin may address items impacting owner satisfaction, such as longer-term reliability. It will not have any "Safety Related" designation on the cover. The instructions, however, are also mandatory and must be followed as directed in the Bulletin.

Once a Service Bulletin is released by Skyjack, a copy of the Bulletin will be mailed to the registered and known owners of the equipment in question. To ensure that you receive these Bulletins, Skyjack must be informed of the serial numbers of any equipment that you own. If you have sold or transferred any machine, Skyjack requires that you promptly notify us of the new owner’s contact information. Should you subsequently receive a Service Bulletin for any machine that you have sold or no longer possess, the Bulletin must be forwarded to the new owner of that machine.

It is very important that any Service Bulletin is read thoroughly and understood before attempting to perform the required inspection, repair or modification. Most questions about the work required by a Service Bulletin are alleviated by knowledge of what is to be done, before starting completion of the Bulletin.

Skyjack’s Service Bulletins are available to look at on our website, skyjack.com/bulletins. The Bulletins are identified by number and are in PDF files for easy viewing and downloading. When performing an annual inspection, check the serial number of the unit for any open Service Bulletins by contacting Skyjack Product Support.

If you have any questions regarding how to perform or process a Service Bulletin, or any other question about your Skyjack equipment, please contact Skyjack Product Support at 1-800-275-9522 or email service@skyjack.com.