AERCO BMS 168 - Manual (Page 50)

A-2
Appendix A
(cont.)
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CURRENT LOOP
Input resistance
250 Ohms
Protection Isolated from AC line potential, fuse-protected at
62 mA, open loop detected at <1 mA
Operational current range 4 mA to 20 mA
SET BACK
Input 12 VDC at 15 mA. External short activates circuit;
Open deactivates it
OUTPUTS
SYSTEM START RELAY
Contact Rating 120 VAC at 5 A, fuse protected at 5 A
Operation Relay closes when outside air temperature is less
than the system start temperature setting
FAULT ALARM RELAY
Contact Rating 120 VAC at 5 A, fuse protected at 5 A
Operation Relay closes when valid error condition occurs
AUXILIARY RELAY
Contact Rating 120 VAC at 5 A, fuse protected at 5 A
Operation Relay closes when all available boilers are
operating at maximum power input (fire rate).
Relay can be programmed to close when all
available boilers are at maximum power input or
no boilers are available (all boilers faulted or
turned off).