What would the voltage usually be on the coil of the contactor for
a lathe using a 3 phase motor?. In UK so single phase is 240V ac

It could be anywhere from 12 VDC to 575 VAC. Any markings on the
coil?? Who is the contactor manufacturer??

"golfer" wrote in message
ups.com...
It could be anywhere from 12 VDC to 575 VAC. Any markings on the
coil?? Who is the contactor manufacturer??


All I know is the coil has failed, not obviously overheated but now open
circuit .
It consists of 5,200 turns of 40SWG. Heavily modified lathe with
contactor changed 20 years ago with an unknown make one.
Only the coil is in my possession, removed by owner wanting rewinding and I
wanted some idea what
I'm likely to find on refitting the coil.

Can you reverse engineer the circuit ?
I guess you have a normally closed contact (Emergency / Off push button) in
series with the coil. Then in series with it, two normally open contacts
connected in parallel together. The first one is the On push button, the
second one is an auxiallary contact of the relay, closing at the same time
as the three-phase power contacts. All the circuitry is powered under 240
Vac.

If the mains is 240 Vac, there's 240 V between one phase and the neutral.
Between two phases, there's 415 Vac.
Should you have a Delta / Star starter, this shouldn't change anything in
the voltages nor the commands since this is a standard circuit.

Didn't the UK stick to European 230 Vac +/- 10% rules ?

a lathe using a 3 phase motor?. In UK so single phase is 240V ac

Does this mean that you're using a three-phase motor on a single phase main,
using a capacitor to shift the third phase ?
If yes, normally the motor isn't able to start from itself without changing
the capacitor value during the starting period. The circuitry is a little
bit more tricky and this an uncommon arrangement. The relay could be
anything.

Please clarify

"N Cook" wrote in message
...
What would the voltage usually be on the coil of the contactor for
a lathe using a 3 phase motor?. In UK so single phase is 240V ac

It's either 415 VAC or you have an oddly complex starter - I assume it's a
starter and has thermal overloads installed.
--
N

"N Cook" wrote in message
...
What would the voltage usually be on the coil of the contactor for
a lathe using a 3 phase motor?. In UK so single phase is 240V ac



Measure it...

Even a cheap DMM should go as high as you'll possibly find there.

N Cook wrote:

What would the voltage usually be on the coil of the contactor for
a lathe using a 3 phase motor?. In UK so single phase is 240V ac


most likely 240V, i am from the US and we use 120 normally for the
coil which also matches our resident common voltage. we do also
use 220..240 coils in Foreighn machines that we have.
in the case of your lathe, normally we use manual contactors,
this means no coil is neeeded. i mite what to consider that .

"Jamie" wrote in message
...

What would the voltage usually be on the coil of the contactor for
a lathe using a 3 phase motor?. In UK so single phase is 240V ac

most likely 240V, i am from the US and we use 120 normally for the
coil which also matches our resident common voltage. we do also
use 220..240 coils in Foreighn machines that we have.
in the case of your lathe, normally we use manual contactors,
this means no coil is neeeded. i mite what to consider that .

If you use 220/380 your coil would be 380. No-one runs a neutral to a
starter just to run the coil.
--
N

- 220/380 doesn't exist anylonger. 230/400 instead.

- My experience is the opposite of your statement.


"NSM" a écrit dans le message news:
fafMd.98522$Ob.5382@edtnps84...

"Jamie" wrote in message
...

What would the voltage usually be on the coil of the contactor for
a lathe using a 3 phase motor?. In UK so single phase is 240V ac

most likely 240V, i am from the US and we use 120 normally for the
coil which also matches our resident common voltage. we do also
use 220..240 coils in Foreighn machines that we have.
in the case of your lathe, normally we use manual contactors,
this means no coil is neeeded. i mite what to consider that .

If you use 220/380 your coil would be 380. No-one runs a neutral to a
starter just to run the coil.
--
N

"Aldo Larrabiata" wrote in message
...
- 220/380 doesn't exist anylonger. 230/400 instead.

- My experience is the opposite of your statement.

In the USA?
--
N

"N Cook" wrote in message
...
"golfer" wrote in message
ups.com...
It could be anywhere from 12 VDC to 575 VAC. Any markings on the
coil?? Who is the contactor manufacturer??


All I know is the coil has failed, not obviously overheated but now open
circuit .
It consists of 5,200 turns of 40SWG. Heavily modified lathe with
contactor changed 20 years ago with an unknown make one.
Only the coil is in my possession, removed by owner wanting rewinding and
I
wanted some idea what
I'm likely to find on refitting the coil.



followup - was actually 6,200 turns of 40 SWG rewound and
working - coil volts are 240V and make/model of contactor
was MTE UC15 440 50

"N Cook" wrote in message
...

followup - was actually 6,200 turns of 40 SWG rewound and
working - coil volts are 240V and make/model of contactor
was MTE UC15 440 50

What volts are actually applied across the contactor coil?
--
N

240 V ac

"NSM" wrote in message news:cn%Md.1518$L_3.366@clgrps13...

"N Cook" wrote in message
...

followup - was actually 6,200 turns of 40 SWG rewound and
working - coil volts are 240V and make/model of contactor
was MTE UC15 440 50

What volts are actually applied across the contactor coil?
--
N

"N Cook" wrote in message
...
240 V ac

They ran a neutral to do this then? Odd.
--
N