With a 230 V AC, 50 Hz coil and a motor rating of 37 kW at 400 V, the Siemens 3RT2045-1AP00 is the size S3 member of the SIRIUS 3RT2 contactor range for 80 A AC-3 duty. It has 1 NO + 1 NC integrated auxiliary contacts, and Siemens rates it at 125 A for resistive (AC-1) loads at 40 °C. At 230 V the AC-3 motor rating is 22 kW.
A contactor is the switching element of a motor starter: the PLC or a push-button energises the coil, and the main contacts connect the motor to the supply. Contactors wear with every start, so they are among the most frequently replaced parts in motor control centres.
See our Siemens industrial controls range, including SIRIUS 3RU2 overload relays and 3RV2 motor starter protectors for the same size.
Technical data
| Siemens order number | 3RT2045-1AP00 |
|---|---|
| Product | SIRIUS 3RT2 power contactor, 3-pole |
| Size | S3 |
| Utilisation category | AC-3 / AC-3e |
| Rated operational current AC-3 at 400 V | 80 A |
| Motor power AC-3 at 400 V | 37 kW |
| Motor power AC-3 at 230 V | 22 kW |
| Operational current AC-1 (40 °C, up to 690 V) | 125 A |
| Rated operating voltage, max. | 1,000 V |
| Coil voltage | 230 V AC, 50 Hz |
| Coil operating range | 0.8 … 1.1 x Us (50 Hz) |
| Coil pick-up power (50 Hz) | 296 V·A |
| Coil holding power (50 Hz) | 19 V·A |
| Auxiliary contacts (integrated) | 1 NO + 1 NC |
| Closing delay | 13 … 50 ms |
| Opening delay | 10 … 21 ms |
| Mechanical service life, typ. | 10,000,000 operating cycles |
| Power loss per pole (rated current) | 5.3 W |
| Short-circuit protection, main circuit (type 1) | gG: 250 A (690 V, 100 kA), aM: 160 A (690 V, 100 kA), BS88: 200 A (415 V, 80 |
| Ambient temperature (operation) | -25 … +60 °C |
| Connection type | screw-type terminals |
| Mounting | screw and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715 |
| Dimensions (W x H x D) | 70 x 140 x 152 mm |
| Net weight | 1.636 kg |
| Condition | New, original Siemens |
Typical applications
- Switching heaters and resistive loads (AC-1)
- Pump, fan and compressor control panels
- Star-delta starter assemblies
- Direct-on-line starters for motors up to 37 kW at 400 V
Compatibility and replacement
For overload protection mount a SIRIUS 3RU2 thermal overload relay of size S3 directly under the contactor, or combine it with a 3RV2 motor starter protector of the same size using the Siemens link module. Auxiliary contact blocks (3RH2911) can be snapped on the front to add more NO/NC contacts.
Frequently asked questions
Can I use it for a 7.5 kW motor?
This contactor is rated 37 kW at 400 V (AC-3, 80 A). Choose a contactor whose AC-3 rating at your supply voltage is at least the motor rating.
How many auxiliary contacts does it have?
It has 1 NO + 1 NC integrated; more can be added with 3RH2911 auxiliary switch blocks.
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.
Every part RendatSP supplies is new and original, carries a 1-year warranty and ships worldwide by air in 5 to 7 days once ready (shipping, payment and warranty). Send us the order number and quantity on WhatsApp or through the inquiry form and we will quote the same working day. Agents in Saudi Arabia, Iraq, the UAE, Egypt, Oman, Libya, Morocco, Mauritania, Yemen, Algeria and Jordan.
