Allen-Bradley 1492-SPM1C040 Bulletin 1492-SP Supplementary Protector

Configured for overcurrent protection in control circuit branches, the Allen-Bradley 1492-SPM1C040 (1492-SPM1C040 Supplementary Protector) provides direct physical/electrical execution of single-pole circuit interruption under overload and short-circuit conditions.

Hardware Specifications

Profinet / EtherNet/IP Deterministic Networks

The 1492-SPM1C040 utilizes a thermal-magnetic trip unit to provide instantaneous response to fault events. This protector is designed for mounting within standard control enclosures where I/O density scaling necessitates individual branch circuit isolation. While this device serves as a mechanical circuit protection component, its operation is governed by standard electrical coordination protocols. Users must ensure the protector is matched to the load requirements and that the upstream fault current does not exceed the device's rated breaking capacity. Firmware flash compatibility and deterministic network diagnostics are handled by secondary monitoring devices where status feedback is required for supervisory logic.

Frequently Asked Questions

Q: Can this 1-pole protector be used for motor branch circuit protection?

A: No. The 1492-SPM1C040 is classified as a supplementary protector and is intended for protection of control circuits and instrumentation. It does not meet the requirements for a UL-listed branch circuit protector intended for direct motor branch circuit protection.

Q: Does the C-curve trip characteristic allow for inrush current?

A: Yes. The C-curve is specifically designed for general-purpose applications with moderate inrush currents. It allows for higher transient currents during the initial energization phase without causing nuisance tripping, while maintaining tight protection against sustained overloads and short circuits.

Field Installation Guidelines

1. Mount the protector onto a standard 35 mm DIN rail; ensure the mounting latch is fully seated to provide mechanical stability.
2. Observe the designated line and load terminal orientations; incoming power should be connected to the upper terminals.
3. Utilize copper conductors sized according to the 4 A continuous current rating to prevent excessive heat generation at the termination points.
4. Separate the protected control circuit wiring from high-voltage power lines or variable frequency drive cables to mitigate electromagnetic noise.
5. Apply the correct tightening torque to the clamp terminals as specified in the technical manual to ensure a low-impedance electrical path.
6. Perform a continuity test upon completion of wiring to verify that the circuit is correctly established and that the breaker is functional in the "ON" position.