1950’s Selecta suds pump wiring – capacitor?

[Adam HarrisParticipant @adamharris13683]

[Adam HarrisParticipant @adamharris13683]

I have an old single phase 0.1 hp suds pump made by Selecta that has 4 terminals (each marked 1, 2, 3, 4) plus an earth. The wiring label states clearly that the mains circuit should be connected to the 1 and 3, and the capacitor circuit should be connected to 1 and 2. The problem is that there is no capacitor and no marks where it might have been mounted to the pump. Is it possible that in the 1950's these pumps had a remotely mounted capacitor? Or is the capacitor possibly a very thin component embedded in the resin surround of the Run wiring? Or were they sometimes connected to the capacitor circuit of the lathe drive motor thus piggy backing off it? (I am aware that a normal capacitor start induction run motor has quite a substantial externally mounted capacitor). What would happen if I assumed the capacitor was somehow embedded inside so just wired up the 'capacitor circuit' (1 &2) to the mains wiring ? Any advice welcome?

[Adam HarrisParticipant @adamharris13683]

And if I need to buy a separate capacitor, how do i determine the required spec of the capacitor from the spec details of the motor?

[Stuart BridgerParticipant @stuartbridger82290]

Are you sure it is a single phase motor?
The connections sound a bit like how you would wire a 3 phase motor to run off single phase using a motor run cap?

[ronan walshParticipant @ronanwalsh98054]

It sounds like a three phase motor that some one has "converted" to single phase by putting a capacitor across two of the legs.

[Nick_GParticipant @nick_g]

.

Are there 3 wires internally connected already to terminal 4.?

If so there is a possibility the previous 2 posters are correct.

Nick

[Adam HarrisParticipant @adamharris13683]

Thanks for the responses – the manufacturers spec plate clearly states '1 PH' and there are no connections to 4. There is a printed loose label giving wiring instructions inside. I think it must have had a remote capacitor but I have never encountered such an idea before. Does anyone know by the Run circuit's amps, hp and voltage how to calculate the farads of a capacitor required?

[Adam HarrisParticipant @adamharris13683]

A website capacitorguide dot com provides the answer. Thanks for the effort from responders. Enquiry closed.

[john fletcher 1Participant @johnfletcher1]

I am not familiar with a Selects motor, but I have had a look via Google and it would appear to be a capacitor start motor. Perhaps you could have a look inside to see if there is a centrifugal switch which would confirm that it is a capacitor start. You haven't published any details regarding the wattage of the motor which might give a clue as to the micro farad capacity of the capacitor. The actual micro farad rating is not precise some thing in the region of 60/70 could be OK as they are often plus / minus 20% anyway. The working voltage should be at least 260 and they special AC electrolytic motor start type. I notice that Selecta list a permanent capacitor type motor as well with a 500 micro farad capacitor. If you have a motor rewind shop near by they will know the value and sell you one. It can be mounted close by in an earthed metal box.Ted

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