DC Motor - Please Help
DC Motor - Please Help
(OP)
Hi,
I have brushed motor I need to get up and running but the only info I have on it is its DC 90V.
I guess it's shunt wound as in the junction box there are 4 wires, BUT when I got it the junction box had been fiddled with and these 4 wires were wired to make a series configuration. I know its been bodged about a bit but any idea how to tell what it should actualy be, from its physical characteristics?
There is no plate on it and no manufacturer info, all I know is its pretty old. 1960's..
I measured the resistance and the field was 2 Ohm and the armature 4 Ohm. Do these seem normal? I thought they are very low so may indicate it has burnt out.
Any thoughts would be welcome.
Thanks
Will
I have brushed motor I need to get up and running but the only info I have on it is its DC 90V.
I guess it's shunt wound as in the junction box there are 4 wires, BUT when I got it the junction box had been fiddled with and these 4 wires were wired to make a series configuration. I know its been bodged about a bit but any idea how to tell what it should actualy be, from its physical characteristics?
There is no plate on it and no manufacturer info, all I know is its pretty old. 1960's..
I measured the resistance and the field was 2 Ohm and the armature 4 Ohm. Do these seem normal? I thought they are very low so may indicate it has burnt out.
Any thoughts would be welcome.
Thanks
Will





RE: DC Motor - Please Help
2 Ohms is too low for a 90 Volt shunt field.
Either a burnt out field.
OR
A series motor.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: DC Motor - Please Help
The reason why armature resistance seems to be changing is that a voltage is induced when you turn the shaft. So, you can also use the V range of the DMM.
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: DC Motor - Please Help
Generally is one more common?
RE: DC Motor - Please Help
RE: DC Motor - Please Help
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: DC Motor - Please Help
Guess this should give a good indication of success.... ???
Also any idea for an extremely economical way of getting a 90V dc source if this does work? Would rectifying and smoothing a 110V AC be alright? Guess I'd need a rheostat or similar to bring the voltage down a bit...
RE: DC Motor - Please Help
RE: DC Motor - Please Help
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: DC Motor - Please Help
RE: DC Motor - Please Help
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: DC Motor - Please Help
Motor is not burnt out and run smoothly on 12VDC when wired in series!
So... the next challenge is to find a suitable starter for it to run at full power... Any ideas for a cheap one?
Thanks for all your help so far.
RE: DC Motor - Please Help
RE: DC Motor - Please Help
I read somewhere you can run dc series motors on ac too? Sounds dodgy what with inductances etc but do you know if this truth in this?
RE: DC Motor - Please Help
RE: DC Motor - Please Help
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: DC Motor - Please Help