Chamberlain K001A5729, Manual

Page: 13 / 65

13
Look For Green “POWER” LED
The Industrial Duty Logic Operator has many features reducing time required to identify and make repairs, as well
as time spent training service technicians. Please note when working on an operator, always follow proper electrical
safety guidelines and local codes.
The transformer should produce 24VAC (±10 %) on the secondary side. If the green power LED, which is located near
terminal 13, is illuminated then 24VAC is present on the logic board. Verifying with a multimeter is still recommended.
To check the secondary side of the transformer, set the meter to volts AC and check across the yellow and blue wires
on the transformer or terminals 13 and 14 on the logic board. If working properly, they should each show 24VAC +/-
10%.
The logic board and all the controls are run on 5VDC. The 5VDC control signal allows 1000 ft. control runs with
18AWG wire. Be sure any incoming signal to the board is from a dry contact and not a voltage source. A dry contact,
such as a standard switch, is a device connecting two wire leads to make a closed circuit. Some examples are the open
or close buttons on LiftMaster’s standard 3-button control station, limit switches and standard relay outputs.
If the green “POWER” LED does not turn on, the transformer may not be working correctly. Verify primary voltage
feeding the transformer by checking: Logic 3.0 and Logic 4.0 - White and Brown wires. Logic 5.0 - Common and
appropriate wire. See the chart for high voltage wires.
Transformer - High Voltage Color Code
Check Control Station
Verify the control stations are wired to the terminal strip correctly. This is easily checked by using the “OPEN,”
“CLOSE”, and “STOP” LED diagnostic LEDs. The operator should have the “OPEN” and “CLOSE” LEDs off and the
green “STOP” LED on.
Turn the selector dial to DIAG to put the operator in diagnostic mode. Confi rm the wiring is correct on the
board by pressing the “OPEN” and “CLOSE” button on the board separately. When each button is pressed, the
corresponding LED should turn on. When working properly, the STOP LED should be illuminated. Pressing the STOP
button should make this LED turn off. If the LED’s respond accordingly to the on-board OPEN/CLOSE/STOP buttons,
test the 3-button control station or the wiring to the 3-button control station.
To test the 3-button control station, open the control station and use a multimeter to verify continuity. When working
properly, an idle 3-button control station with no depressed buttons should read infi nite resistance (open circuit)
across the “OPEN” and “CLOSE” buttons and 0 Ohms (closed circuit) across the “STOP” button. The meter should
read 0 Ohms (closed circuit) when the “OPEN” and “CLOSE” buttons are pressed, and infi nite resistance (open circuit)
when the “STOP” button is pressed. If the continuity test on the 3-button control station yields different results than
listed, the control station will have to be replaced.
NOTE: Don’t run control wiring and power wiring in the same conduit, these wirings should be separated by 18”.
B
Troubleshooting
Industrial Duty Logic Operators
LOGIC 3.0 AND LOGIC 4.0 LOGIC 5.0
115V Brown and White White and Gray
208/230V Single Phase Brown and White White and Purple
208/230V Three Phase Brown and White White and Gray
460V Brown and White White and Purple
575V Brown and White White and Gray