Johnson Controls IFC-1010 Technical Manual page 52

Monitoring
Remote Power
Supplies
MPS-TR Main
Power Supply
N18
Monitor
MPS-TR
Installation
52 Hardware Installation—Installing the IFC-1010/2020
Test of Ground Fault Detection Circuit
If you have a persistent ground fault and suspect the MPS-24A ground
fault detection circuit may be generating a false indication, use this test:
1. Remove the upper right circuit board mounting screw, just to the right
of P2.
2. Insert an insulator (a piece of paper will do) between the power supply
circuit board and the mounting standoff.
If the ground fault indication remains, the problem is with the MPS-24A.
The MPS-24A depends on the CPU-1010/2020 or the XPP-1 to control its
battery charging circuit and to monitor the battery state approximately
every four minutes. If you use the MPS-24A in a remote application from
the main control panel or a transponder, add the MPS-TR to the power
supply to prevent problems keeping the batteries charged. The MPS-TR
has a trouble relay that should be monitored by a system monitoring
device. Note that the CPU or the XPP-1 can control only one power
supply.
The MPS-TR power supply monitor mounts on any of the MPS series
power supplies. (Figure 34) This add-on board mounts on the right side of
the MPS series supply and it is fastened through the use of two extended
length standoffs, making use of threads on the existing standoffs
(Figure 33).
The MPS-TR monitor provides supervision for remote power supplies and
control of the power supply battery charger. The board is mounted and
secured as described above. P1 on the MPS-TR is connected to P3 on the
power supply via a power ribbon (Part Number 71085) supplied with the
MPS-TR. The relay common and normally closed contacts of the MPS-TR
are connected to a normally closed TROUBLE INPUT on the control
panel trouble monitoring circuit.
To install MPS-TR:
1. Remove the upper and lower screws on the right side of the power
supply main board.
2. The MPS-TR mounts on these two holes. Thread the new longer
screws and the standoff sleeves into the holes formerly occupied by
the two screws removed in Step 1.