Rated 32 A / 15 kW at 400 V (AC-3), the Siemens 3RT2027-1AL20 is a 3-pole SIRIUS 3RT2 contactor, size S0, operated by a 230 V AC, 50/60 Hz coil. It has 1 NO + 1 NC integrated auxiliary contacts, and Siemens rates it at 50 A for resistive (AC-1) loads at 40 °C. Siemens quotes a typical mechanical life of 10,000,000 operating cycles for this contactor.
In a direct-on-line or star-delta starter the contactor does the actual switching, while the overload relay or motor starter protector provides protection. A worn contactor shows burnt contacts, humming or chattering, and failure to pull in.
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 | 3RT2027-1AL20 |
|---|---|
| Product | SIRIUS 3RT2 power contactor, 3-pole |
| Size | S0 |
| Utilisation category | AC-3 / AC-3e |
| Rated operational current AC-3 at 400 V | 32 A |
| Motor power AC-3 at 400 V | 15 kW |
| Motor power AC-3 at 230 V | 7.5 kW |
| Operational current AC-1 (40 °C, up to 690 V) | 50 A |
| Rated operating voltage, max. | 690 V |
| Coil voltage | 230 V AC, 50/60 Hz |
| Coil operating range | 0.8 … 1.1 x Us (50 Hz) |
| Coil pick-up power (50 Hz) | 81 V·A |
| Coil holding power (50 Hz) | 10.5 V·A |
| Auxiliary contacts (integrated) | 1 NO + 1 NC |
| Closing delay | 8 … 40 ms |
| Opening delay | 4 … 16 ms |
| Mechanical service life, typ. | 10,000,000 operating cycles |
| Power loss per pole (rated current) | 2.3 W |
| Short-circuit protection, main circuit (type 1) | gG: 125 A (690 V,100 kA), aM: 50 A (690 V,100 kA), BS88: 125 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) | 45 x 85 x 97 mm |
| Net weight | 0.403 kg |
| Condition | New, original Siemens |
Typical applications
- Switching heaters and resistive loads (AC-1)
- Star-delta starter assemblies
- Replacement of a worn 3RT2 contactor with the same rating
- Direct-on-line starters for motors up to 15 kW at 400 V
Compatibility and replacement
For overload protection mount a SIRIUS 3RU2 thermal overload relay of size S0 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
What coil voltage does it need?
Per Siemens: 230 V AC, 50/60 Hz, operating range 0.8 … 1.1 x Us (50 Hz).
How many auxiliary contacts does it have?
It has 1 NO + 1 NC integrated; more can be added with 3RH2911 auxiliary switch blocks.
Can I get a price and delivery time?
Prices are quoted on request. Send the order number, quantity and delivery country on WhatsApp and we will reply with price and delivery time; air shipping is usually 5 to 7 days once ready, with a 1-year warranty.
Before you order
Compare the complete order number on the old unit with this page, including the suffix: in most ranges the last characters set the coil voltage, current range or version. If the label is worn, send us a photo and we will identify the part.
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.
