SIEMENS
SIEMENS 3RH29111FA04 auxiliary contact block 4NC front mount IP20 690V AC
Adds four normally-closed contacts to SIRIUS contactors via front-mount screw terminals rated 690 V AC and IP20
- Four normally closed contacts expand control logic
- Front-mount design fits SIRIUS 3RH2 and 3RT2 contactors
- Screw terminals accept standard wiring tools
- IP20 rating protects against solid objects
- Rated for 690V AC maximum voltage
Front-mount auxiliary contact block
The SIEMENS 3RH29111FA04 provides four normally-closed contacts in a front-mount housing for SIRIUS 3RH2 contactor relays and 3RT2 contactors. It suits panel builders expanding control circuits on frame sizes S00, S0, S2 and S3 as well as NEMA sizes 0 and 00. The IP20-rated enclosure protects terminals from finger contact during commissioning. Screw terminals accept standard wiring practice without special tools.
Thermals noise and power draw
As a passive auxiliary block the unit draws no control power and generates no audible noise or measurable heat in normal operation. Its 690V AC maximum voltage rating defines the insulation limit for the circuits it switches. Contact resistance remains stable across the rated temperature range of the host contactor. No fan, cooling clearance or derating is required for the block itself.
Four normally-closed contacts
The decisive specification is the 0NO/4NC contact arrangement which only breaks circuits when the host contactor energises. Applications needing any normally-open function must select a different auxiliary block. Compatibility is limited to the SIRIUS series and frame sizes listed above. Buyers requiring normally-open contacts or a different mounting style cannot use this part.
Highlights
- Four normally closed contacts expand control logic
- Front-mount design fits SIRIUS 3RH2 and 3RT2 contactors
- Screw terminals accept standard wiring tools
- IP20 rating protects against solid objects
- Rated for 690V AC maximum voltage
Specifications
| Brand | SIEMENS |
|---|
Questions about this item
How do I front-mount this auxiliary contact block onto a SIRIUS 3RT2 contactor and what step is often missed?
Align the block with the contactor front face, press until the latch clicks, then tighten the four screw terminals — skipping the latch check leaves the block loose.
What maintenance will the four normally-closed contacts need over time?
Periodically inspect the screw terminals for tightness and check contact tips for erosion; replace the block if any contact fails to open cleanly.
At what voltage does the 690 V AC rating become the limiting factor during continuous operation?
The 690 V AC maximum voltage rating is the first limit reached; sustained operation above that level exceeds the block's insulation coordination.
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