Table of Contents
Issue:
MP501 not driving tri-state modulating actuator closed or open. Measures only 8V.
Resolution:
A UL-listed Class 2 transformer providing 70 VA at 24 Vac is required to power the Tracer MP501 and associated output relays and actuators - 10 VA for the board and 60 VA for the relays and actuators.
Isolate the boards on separate power to see if the problem is solved.
Test
To test the Contact at BO 1, disconnect the actuator wire from BO1 and ground it to the frame to see whether the actuator drives.
If it does drive, then it's likely the MP501 is either not grounded properly.
Another possibility is that there is enough leakage on the circuits that both circuits want to drive. In that case you will need to add some load to the circuit. Resistors or isolation relays might help