Re-Wiring Lathe Switches

[SillyOldDufferModerator @sillyoldduffer]

Posted by Brian Hutchings on 06/11/2016 19:52:15:..

…

obviously done by a works electrician with only a single reel of red covered wire…

Trivia time.

One reason that a single colour is often used throughout equipment wiring is to highlight later modifications and repairs. Different coloured wiring indicates a change.

It makes it easier for a diagnostician to see what's different. He can identify which version of a circuit he's dealing with, and also see if someone else has already been 'at it'. Quite often faults are related to previous repairs or new features.

Dave

[Brian HParticipant @brianh50089]

Useful point, I hadn't thought of that.

[Roger BettaneyParticipant @rogerbettaney54127]

Could you pass this message onto steve pavey. Hi your wiring diagram in the above is quite useful but contains a little error which may be effecting a few users operating boxford lathes. The starter fitted to my boxford is basically a 3 pole relay with a 3 pole overload. Similar to the one indicated in your wiring diagram. These are primarily designed for 3 phase operation so the load currents in the overload unit are balanced under normal operation. Ie equal currents going through each overload elements. If the currents go out of balance, ie not equal, they will cause the overload to trip out on out of balance protection. Now when using these on single phase motors, one of the wires going through an overload must be doubled back and wired through another overload element to ensure all the three overload elements have the same load current flowing through them. This will avoid the overload nuisance tripping when in normal operation.

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