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APCMON2 Heater Load & Solid State Relay Monitor

APCMON Assembly
APCMON Assembly



Product Description

The APCMON2 is designed to monitor any Anacon Power & Controls Solid State Relay Assembly or any "Hockey Puck" Style Solid State relay. The same high quality relay specification will be met for this series of products. as the APCMON2 Monitor Card mounts directly to the Input and output terminals of the SSR, standard wiring for input control or output connection will follow standard wiring protocol and it's operation will not be affected by the addition of the APCMON2 Monitor.

The monitor card, when wired correctly, will provide an extra level of safety by monitoring the input signal and the output voltage for a shorted SSR, open heater load, loss of AC main supply and DC input power. In critical applications where you need to be assured that the system is always operating properly, the APCMON2 is a smart choice for such applications.

Ordering Information

Please note that the APCMON2 Relay Monitor can be mounted to any APC Solid State Relay Assembly's by adding the Suffix -MON2, ie. APCXXXX-MON2, to the part number. Please contact our sales department for  pricing and availability.

Input Specifications:

Part Number


Power Supply Voltage Range (Vdc)

Control Input (Vdc)



Control Input Impedance (Ohms)

Load Sense Input Voltage Range (Vac; 50/60Hz)

Input-to-Line Isolation Voltage (Vrms, 25°C for 1 second)

Maximum Off-State Blocking Voltage (Vpk for 1 minute)

Maximum Off-State Leakage Current (RMS)






200mS (with control input off)
750mS from last off-cycle (1 sec cycle time 50% duty cycle)
2.5 Sec from last off-cycle (1 sec cycle time 95% duty cycle)
Up-to 15 seconds when using the interrupted Input

Response Time

Alarm Output Specifications:

Relay contact maximum rating = 0.05A / 48Vdc (resistive loads only)
Contacts open upon fault or loss of power.
Contacts are closed when no faults are present.

General Specifations:



Operating Temperature Range

Storage Temperature Range

-0 to +50 °C

-40 to +100 °C

Dimensions & Signals

Mechanical Drawing

Continuous Mode: The control input is wired to the standard IN- and IN+ of the SSR input terminals for continuous
mode operation.
Interrupted Mode: The control input is wired to the IN- of the SSR and the INT IN+ of the
APCMON2. Interrupted
mode provides a brief off signal of 150mS every 15 seconds to test the input to output logic of the relay.


*Notes: To reliably detect an open load, the load current must drop below 60uA when the load is opened. Any
residual leakage in the wiring or load break may cause the
APCMON2 to not be able to detect the open load
condition. Using the
APCMON2 with an SSR that has an on-board snubber will improve the reliability of the
detection because it will present a lower impedance to the load circuit and raise the 60uA detection threshold to a higher value, typically around 300uA. If that threshold is not high enough, a power resistor or external R-C snubber (0.47uF/100R) may be added in parallel with the SSR output. The resistor or snubber should be chosen so that when the load is open, the voltage across the SSR drops below 20VAC.

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