DiversiTech Definite Purpose Contactor C340B

The DiversiTech C340B is a three pole definite purpose contactor rated 40 amps with a 120 volt coil.

Short cycling shortens contactor life more than almost any other operating condition, and it is worth recognising because the contactor is the symptom rather than the cause.

Every time a contactor closes onto a compressor, the contacts carry locked rotor current for a moment, which may be five or six times the running current. That surge is what pits contacts. A system cycling normally makes this transition a few times per hour; a short cycling system may do it many times per hour, multiplying contact wear proportionally.

The causes of short cycling are various: an oversized system satisfying the thermostat too quickly, a thermostat with too narrow a differential or located poorly, low refrigerant charge tripping a pressure control, a dirty condenser raising head pressure, or restricted airflow. A contactor replaced repeatedly on the same equipment is a strong indication that one of these is present.

Fitting a time delay or an anti-short-cycle control addresses the symptom; finding the cause addresses the problem.

At 40 amps in three poles this suits moderate three phase compressor and motor loads.

Applications include commercial air conditioning and refrigeration equipment with line voltage control.

Brand

DiversiTech

SKU

C340B

Category

Contactors

Weight

1.25 lbs

Dimensions

3.80" x 3.00" x 2.50"

Price

$30.00

Availability

In stock

Rating

4.7 / 5.0