Speed control system for central heating pump motor - uses winding connections in socket on end of motor selectively bridged by plug to give required operating speed

摘要

The speed changing system is applicable to small water pumps, for example in central heating installations, where it may be necessary to select a speed to suit the particular operating conditions. This can be achieved by bringing the winding ends out to a socket and selecting the particular star or delta, and series or parallel connection for the required speed by means of a plug with suitable bridging contacts. The supply connection is made permanently to the motor. The plugs are marked and polarised to help to prevent incorrect selection. Where an automatic or remote switch-over in speed is needed, a cable may be brought from the plug pins to a suitable remote switch.