H4137 is a SIL3 safety relay module from German HIMA, used for load switching and signal isolation in safety circuits. It is compatible with H41q/H51q systems and meets the safety requirements of scenarios such as ESD/BMS/F&G. 

I. Basic Information

Model: H4137

Brand: HIMA (Germany)

Type: Safety Relay Module (Single Channel)

Safety Level: SIL3 (IEC 61508), AK6, PL e/Cat.4

Certifications: CE, UL, TÜV, ATEX/IECEx (for explosion-proof areas)

Installation: 19-inch standard rack / DIN rail, compatible with H41q series

Environment: IP20; Operating temperature **-25℃~+60℃**, Storage temperature - 40℃~+85℃

II. Core Parameters

Control Power Supply: 24VDC (±15%), Current ≈ 20mA

Output Contacts: 1 SPDT Conversion Contact (NO/NC/COM)

Contact Capacity: ≤ 250VAC/VDC, ≤ 4A (Safety Application ≤ 60% of Rated Value)

Switching Power: AC ≤ 1000VA (cosφ > 0.5); DC ≤ 120W (30V)

Action Time: Clamping ≈ 7ms, Release ≈ 5ms

Insulation Strength: Input/Output ≥ 500VAC, Isolation Voltage Rating ≥ 1500VAC

III. Terminal Definitions (Standard) Table

Terminal Function

1 +24VDC (Power +)

2 0V (Power -)

3 IN+ (Control Signal +)

4 IN- (Control Signal -)

5 COM (Common Contact)

6 NO (Normally Open)

7 NC (Normally Closed)

IV. Working Principle and Safety Characteristics

Safety Isolation: Electrical isolation between the control side and the load side to prevent cross-circuit failure spread.

Fault Safety: When power is lost / in case of a fault, the relay is forced to open, and the output is in a safe state (compliant with ESD "Power Loss Safety").

Self-Diagnosis: Real-time self-check of power, coil, and contacts. System alarms are triggered when faults occur (requires HIMA system in conjunction).

Explosion-proof Design: Suitable for Zone 2/22 hazardous areas, meeting explosion-proof safety requirements.

V. Installation and Wiring

Installation: Vertical installation of the frame, with a spacing of ≥ 20mm for heat dissipation; away from strong electromagnetic interference, corrosive / dusty environments.

Wiring: Power-off operation, with cable ≤ 2.5mm²; separate wiring for power, signal, and load, away from power lines.

Shielding: Single-ended grounding of the signal cable shielding layer to reduce interference.

VI. Debugging and Maintenance

Power-on Test: Power-on without load, the power LED lights up; supply 24VDC control signal, NO closes, NC opens.

Daily Maintenance: Check wiring and contacts for no burnout every 6 months; power off and use dry air to blow away dust.

Fault Troubleshooting:

Not Engaged: Check 24VDC, input signal, coil → replace module;

Contact Adhesion: Overload / Frequent operation → reduce load to 60% rated value, replace module;

Alarm: Incorrect wiring / Internal fault → review wiring, return for repair.

VII. Typical Applications

Petrochemical / Chemical: ESD emergency stop, BMS burner management, F&G fire gas system;

Oil and Gas / Power: Hazardous area valve control, burner safety interlock, critical equipment shutdown protection;

Compatible Systems: H41q/H51q series SIS, compatible with H4135 (CPU), H4136 (redundant relay).

VIII. Differences from H4136

H4137: Single channel, single contact, focusing on signal isolation and small load drive, lower cost;

H4136: Three-channel redundancy, three contacts, focusing on high safety redundancy load drive, suitable for high-risk SIL3 circuits