Liebert TM-10098 Basic Troubleshooting Steps, iCOM Controls Training and Service Manual

iCOM Controls Training and Service Manual

Basic Troubleshooting Steps:

Example: Unit load is not energizing.

Programming:

1.Read and record all program parameter values.

2.Read and record all DIP (control) switch positions on all boards. Check all jumpers on each board, check for the CAN healthy light on the boards and check programming per the read and record sheet in appropriate manuals to verify selected options.

3.Turn Unit off with ON/OFF button and reboot system power (disconnect switch off - on) to reconfigure system. If programming error is detected, recheck unit for proper operation.

If problem is not resolved in programming section, begin the signal flow check.

Signal Flow Check: Assumption is the unit is calling for a mechanical operation but the load is not activated. Using the appropriate control training and service manual, identify the output opto-isolator to be checked, locate the opto-isolator on the PCB and perform the following.

DC Voltage check:

1.Using a digital voltmeter check for the correct VDC signal at the output opto- isolator. Pin 1 referenced to - VDC will show low VDC (approximately 1.2 VDC) if the microprocessor control side of the device is functioning. A high VDC (approximately 3.3 VDC) indicates a microprocessor control problem. A meter reading of 0 VDC indicates a loss of microprocessor voltage, check VDC at the power supply referenced +VDC to -VDC should be approximately 3.3 VDC.

2.This check involves the microprocessor. To bypass the microprocessor completely, jumper from Pin 2 on the output opto-isolator to -VDC. As soon as the jumper is applied the load device should activate. If the load device activates the problem is in the microprocessor itself or the programming. If the load device does not activate continue the signal flow check.

AC Voltage check:

1.Place the digital VOM meter on AC voltage scale and verify that 24 VAC is being applied to the output opto-isolator by placing the VOM between Pin 4 and the proper transformer ground connection. To verify that the switch leg of the output opto-isolator is working properly place the VOM between Pin 6 and the proper transformer ground connection. A high VAC (approximately 24 VAC) display indicates a closed switch leg; a low VAC indicates an open switch leg.

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