Siemens 3RT20241AG20 | S0 Class Contactors

Selection trade-offs (3RT20241AG20 vs. catalog peers)

1. Coil voltage selection — must-match control circuit: The 3RT20241AG20 carries a 110VAC coil; the must-operate voltage of 93.5 VAC sets the pull-in threshold. Selecting a contactor with the wrong control-system voltage risks non-energization or contact drop-out during voltage sag.

2. Auxiliary contact count vs. control scheme requirements: The 3RT20241AG20 ships with one normally-open (NO) and one normally-closed (NC) auxiliary contact. Control circuits needing separate status feedback, seal-in, or overload-trip indication should verify that one NO + one NC accommodates the logic — or cross-check the two additional aux contacts offered by 3RT20241AG24.

3. Operating temperature window (25°C ~ 60°C): The stated operating range is 25°C to 60°C. If the enclosure or switchgear environment routinely approaches the upper bound, thermal derating of the 12 A contact rating may be necessary per the applicable coordination standard — a panel-builder qualification step, not a catalog specification.

4. Coil power draw — sizing the control supply: At 68 VA inrush, the 110VAC control transformer or supply must deliver adequate VA during energization. The operate time of 38 ms defines a bounded contact-make window during which the magnetizing inrush dominates.

5. Mounting form factor — chassis vs. DIN rail: Both mounting options are available, but DIN rail adoption simplifies panel layout when using standard Siemens S0 modular bus assemblies. Chassis mount may suit sealed enclosures or space-constrained layouts where rail clearance is limited.

In-catalog comparison (Siemens 3RT2024 family)

The following table lists the primary part alongside catalog peers that share the same base product number. All parts are Siemens electromagnetic contactors in the S0 frame; similarity scores reflect parametric overlap only and do not constitute interchange approval.

Why these parts appear similar

• 3RT20241AG24 (similarity 1.0): Same 110VAC coil and base product number; differs only in auxiliary contact count — two NO and two NC instead of one each. Shares the same must-operate voltage and mounting options. The 1VA difference in coil power and 2 ms longer operate time fall within family tolerances.

• 3RT20241AC20 (similarity 0.96): Same S0 frame, 12 A rating, and auxiliary contact arrangement; the only change is the 24VAC coil. Operate time and coil power are virtually identical to the primary part.

• 3RT20241AL20 (similarity 0.96): Same base product number, same contact form, and same aux configuration; the coil voltage shifts to 230VAC with a must-operate threshold of 195.5 VAC. Coil power is 67VA, marginally lower than the primary part's 68VA.

Specifications

FAQ

What control-circuit voltage is required to reliably pick up the 3RT20241AG20? The must-operate voltage is 93.5 VAC. The coil is designed for 110VAC nominal; ensure the supply stays above 93.5 VAC during energization to guarantee pick-up.

Can the 3RT20241AG20 be used for reversing motor applications? The catalog lists a 3PST-NO main contact form. Reversing requires isolation of all three phases; a standard non-reversing contactor alone does not provide the required mechanical interlock. Reversing configurations typically use a dedicated mechanically interlocked pair of contactors — a panel-design qualification step.

What is the difference between the 3RT20241AG20 and the 3RT20241AG24? Both carry the same 110VAC coil, 12 A rating, and 3RT2024 base product number. The 3RT20241AG24 adds a second set of normally-open and normally-closed auxiliary contacts (2NO/2NC total) versus the 3RT20241AG20's single auxiliary NO and NC pair.