The Siemens 3RV2021-4NA10 is a SIRIUS 3RV2 motor starter protector (circuit breaker for motor protection) in size S0, with a thermal overload release adjustable from 23 … 28 A and a magnetic short-circuit release at 364 A. Per Siemens it suits motors of about 15 kW at 400 V and has a rated short-circuit breaking capacity (Icu) of 55 kA at 400 V.
Unlike fuses, a 3RV2 can be reset after a trip, and its rotary handle clearly shows ON, OFF or TRIPPED, which speeds up fault finding on the shop floor.
See more Siemens industrial controls, including SIRIUS 3RT2 contactors of the same size.
Technical data
| Siemens order number | 3RV2021-4NA10 |
|---|---|
| Product | SIRIUS 3RV2 circuit breaker for motor protection |
| Size | S0 |
| Overload release setting range | 23 … 28 A |
| Instantaneous short-circuit release | 364 A |
| Trip class | CLASS 10 |
| Rated current | 28 A |
| Motor power AC-3 at 400 V | 15 kW |
| Motor power AC-3 at 230 V | 7.5 kW |
| Motor power, 3-phase 460/480 V (UL) | 20 hp |
| Breaking capacity Icu at 400 V | 55 kA |
| Breaking capacity Ics at 400 V | 25 kA |
| Rated operating voltage | 690 V |
| Phase failure sensitivity | Yes |
| Isolating function | Yes |
| Combinable contactor sizes | S00, S0 |
| Power loss (hot, total) | 13.25 W |
| Degree of protection (front) | IP20 |
| Ambient temperature (operation) | -20 … +60 °C |
| Mounting | screw and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715 |
| Dimensions (W x H x D) | 45 x 97 x 97 mm |
| Net weight | 0.355 kg |
| Condition | New, original Siemens |
Typical applications
- Fuseless motor starters with SIRIUS 3RT2 contactors
- Protection of pumps, fans, conveyors and compressors
- Motor branch circuits with full-load currents between 23 … 28 A
- Transformer and control circuit protection where a motor-type characteristic is acceptable
Compatibility and replacement
Auxiliary switches for status feedback can be added on the front (transverse, for example 3RV2901-1E) or on the left side (3RV2901-1A). Choose the setting range so that the motor full-load current sits roughly in the middle of the dial; this leaves room for adjustment.
Frequently asked questions
What motor current can it protect?
The overload release is adjustable from 23 … 28 A. Set it to the rated current shown on the motor nameplate.
Which contactors can it be combined with?
Per Siemens: contactor sizes S00, S0.
What is the short-circuit breaking capacity?
Per Siemens: Icu 55 kA at 400 V, Ics 25 kA.
Do you ship to my country, and what is the warranty?
Yes. RendatSP ships worldwide from Yiwu, China, by air in 5 to 7 days once the part is ready, and every part carries a 1-year warranty. Send the order number and quantity on WhatsApp and we will reply with a quotation.
Ordering tips
Send us the full order number from the label of the old part, or a clear photo of the label, together with the quantity you need. We check the number against the current manufacturer data before we quote and tell you if there is a newer replacement.
RendatSP ships from Yiwu, China, to factories worldwide; air delivery usually takes 5 to 7 days once the part is ready. The part is new and original with a 1-year warranty (shipping, payment and warranty). For a quotation, message us on WhatsApp with the order number and quantity. We also have agents in Saudi Arabia, Iraq, the UAE, Egypt, Oman, Libya, Morocco, Mauritania, Yemen, Algeria and Jordan.
