Siemens 3RT1075-6AR36 Contactor
Engineering verification checklist
- Confirm system coil voltage matches the 440–480 VAC/DC rating before installation
- Verify chassis mounting surface and DIN rail clearance for the S12 form factor
- Check that auxiliary contact features align with the control circuit requirements
- Validate 400 A contact rating against motor full-load current and short-circuit coordination
- Confirm 920 W coil dissipation does not exceed enclosure thermal limits at 25–60 °C
- Inspect box packaging integrity upon receipt; report any damage before rack mounting
- Verify operate time of 100 ms meets timing requirements for the motor starting sequence
- Confirm 3PST-NO (3 Form A) pole configuration matches the power circuit topology
Coil voltage family comparison
The 3RT1075 series shares identical current, power, and mounting specifications across all coil voltage variants. Coil voltage selection must match the available control circuit; the seed unit operates at 440–480 V AC/DC.
| Spec | 3RT1075-6AR36 | 3RT1075-6AV36 | 3RT1075-6AT36 |
|---|---|---|---|
| Coil Voltage | 440–480 VAC/DC | 380–420 VAC/DC | 575–600 VAC/DC |
| Contact Rating | 400 A | 400 A | 400 A |
| Coil Power | 920 W | 920 W | 920 W |
| Contact Form | 3PST-NO | 3PST-NO | 3PST-NO |
3RT1075-6AV36 shares the same Siemens S12 frame and chassis/DIN mounting; its 380–420 V coil sits in a lower band than the seed unit, representing the most proximate voltage tier within the family.
3RT1075-6AT36 targets 575–600 V control circuits, the highest voltage option in the series, still delivering the same 400 A contact rating and 100 ms operate time.
Contact form and thermal considerations
The 3RT1075-6AR36 is a three-pole, normally open contactor rated for 400 A per pole. The 3PST-NO configuration provides three independent Form A contacts for switching three-phase loads such as motors or transformers. With a coil power dissipation of 920 W, thermal management in the enclosure requires attention—particularly when ambient temperatures approach the 60 °C upper limit. The 100 ms operate time specification governs contact gap establishment and directly affects short-circuit withstand when coordinated with upstream protection.