WEG CWM18-00-40V37 : 4-Pole Lighting Contactor, Normally Open, 277VAC / 50-60 Hz Coil, 32A AC-1, UL 508
The WEG CWM18-00-40V37 is a 4-pole contactor with four normally open main contacts and no auxiliary contacts, a 277VAC 50-60 Hz control coil, and published ratings of 32 A under AC-1 at Ue 690 V or less and 18 A under AC-3 at Ue 440 V or less. One control signal switches all four poles together. In this part all four poles are open with the coil de-energized, so the lighting circuits go off when control power is lost.
Before you select this part: it gives you four normally open poles and a 277VAC 50-60 Hz control coil. Match the published utilization category to the load you are switching; WEG does not publish an AC-5a or AC-5b lamp-load rating in the supplied datasheet.
How this contactor is rated
WEG publishes three current ratings for this frame and they are not interchangeable. AC-1 is 32 A at Ue 690 V or less and 55 C or less, which is the general purpose figure for resistive and lightly inductive loads. AC-3 is 18 A at Ue 440 V or less, dropping to 13 A at 690 V, which is the motor figure. WEG's datasheet does not publish an AC-5a or AC-5b rating, which is the utilization category for discharge and incandescent lamp loads. If your specification calls out an AC-5 figure for a ballast or LED circuit, contact us and we will get it confirmed by EE Controls in writing before you order.
Technical specifications
Read from the WEG Contactors datasheet, product code 13323656.
| Specification | Value |
|---|---|
| Catalog number | CWM18-00-40V37 |
| Main contacts (power) | 4 NO |
| Auxiliary contacts | None |
| Control voltage | 277VAC 50-60 Hz |
| Rated utilization voltage Ue, IEC / UL | 690 V / 600 V |
| Rated current Ie, AC-3 at Ue 440 V or less | 18 A |
| Rated current Ie, AC-3 at Ue 690 V or less | 13 A |
| Rated current Ie, AC-1, Ue 690 V or less at 55 C or less | 32 A |
| Rated impulse withstand voltage Uimp | 6 kV |
| Mechanical lifespan | 10 million operations |
| Electrical lifespan, AC-3 | 1.2 million operations |
| Degree of protection, main / control circuit | IP10 / IP20 |
| Terminal type | Screw, M3.5 flat / Phillips |
| Tightening torque, power / control | 15 lb.in / 10 lb.in |
| Installation | Not stated in the WEG datasheet |
| Ambient temperature, operation | -25 C to +55 C |
| Dimensions, height x width x depth | 81 x 45 x 87 mm (3.19 x 1.77 x 3.43 in) |
| Weight | 300 g |
| Standards | IEC 60947-1, UL 508 |
| Certifications | CE, UL, EAC |
EE Controls crossover
EE Controls cross-references the discontinued EE Controls LSN7-400-H to this catalog number. That crossover comes from EE Controls and is not printed in either manufacturer datasheet, so treat it as a vendor-supplied cross-reference rather than a published equivalency, and confirm fit and ratings against your own submittal. The normally closed version of this part is the WEG CWM18-00-04X37.
Datasheets and technical documents
Frequently asked questions
What is the coil voltage on the WEG CWM18-00-40V37?
What current is the CWM18-00-40V37 rated for?
What contacts does the CWM18-00-40V37 have?
How big is the CWM18-00-40V37 and how does it mount?
Why would I choose normally open over the alternative?
Does the WEG CWM18-00-40V37 replace an EE Controls part?
Is the CWM18-00-40V37 rated for ballast and LED lighting loads?
Sources: EE Controls LSN Series Lighting Contactor catalog (nameplate and selection tables); WEG Contactors datasheet, product code 13323656 (CWM18-00-40V37), issue dated 14/09/2026. Crossover part numbers supplied by EE Controls. Reviewed 14 September 2026.
- # of Poles:
- 4
- Coil Voltage:
- 277VAC
- Configuration:
- Normally Open
