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reverses polarity to cause the stepper motor to move in the proper direction. A
shorted stepper motor will almost always damage the driver chips on the Original
Intellisys but will simply illuminate an overload on the SG Intellisys. See FSM for
more information on the SG.
Procedure
Disconnect the Stepper Motor leads from the board. Measure resistance
between (starter interface board BTS-3 and BTS3-7, also BTS3-8 and BTS3-9),
SG Power Supply Board J3 & 2 and J3 1&2 and J3 3&4). If any of these do not
read as an open circuit, then the associated board is faulty.
Next, determine if the driver chips are sending a signal to the Stepper Motor.
Use a driver signal indicator as per page 34 in section “B” of the blue Field
Service Manual.
Connect the signal indicator in parallel with the Stepper Motor leads.
Power the unit up.
The lights should sequence as indicated on the signal sheet. If either set of lights
fails to light or stay on continuously, either the driver chips are bad or the
controller is not sending the step and direction signal.
Next, determine if the controller is sending the direction and step signal. See
below for SG Controller. On the original Intellisys Starter Interface Board
connect a DC voltmeter to terminal number 17 on PAL chip U13 and BTS3-1.
Power the compressor up and see if the voltage changes from 0 to 5 and then
back to 0. If so, the controller is sending the correct direction signal.
Next, connect the DC voltmeter to Terminal 18 on component U13 and BTS3-1.
The step and direction signal for the SG Controller connects to Terminal J4 on
the Power Supply Board. Connect a DC voltmeter to terminal number J4
Terminal 3 and J4 Terminal 2.
Power the compressor up and see if the voltage changes from 0 to 6-12 and then
back to 0. If so, the controller is sending the correct direction signal.
Next connect the DC voltmeter to Terminal 18 on component U13 and BTS3-1.
See FSM Section B, Sheet 26 in the Blue Book for more information on
direction and step signal for the SG Controller.
Summary of Contents for INTELLISYS SSR Series
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