Perhaps ask the supplier of the VFD? I used Drives Direct and their engineer is very helpful. For one machine - a 1930s Boley lathe - it would start but cut out at a certain rpm. He correctly diagnosed damp absorption in the very old motor and recommended baking it. Too heavy for me to get off and put in an oven, but a day in the blast from a fast heater did the trick perfectly.
Wadkin BGS 12" saw motor conversion
- Thread starter jorgoz
- Start date
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jorgoz
Established Member
deleted
Ttrees
Iroko loco!
Jorgoz
Could you clarify if you have read the recent thread I have linked by Memzey
It would be appreciated as many of us have interest in your motor type.
P.S, Before opening the motor up, make a continuous line to aid reassembly again...
It is common practice for the pro's, to have a look inside to check for sawdust.
Thanks
Tom
Could you clarify if you have read the recent thread I have linked by Memzey
It would be appreciated as many of us have interest in your motor type.
P.S, Before opening the motor up, make a continuous line to aid reassembly again...
It is common practice for the pro's, to have a look inside to check for sawdust.
Thanks
Tom
memzey
Established Member
If it’s listed as 400v only on the motor plate you may have to open up the motor and get at the star point connection as I did in the post Ttrees linked to above. Rearranging that connection to delta might be all you need to do in order to get it working, all other factors being ok.
PS - I know very little about these motors beyond what I have read on these boards and researched online so take my suggestion above as coming with a health warning.
PS - I know very little about these motors beyond what I have read on these boards and researched online so take my suggestion above as coming with a health warning.
jorgoz
Established Member
deleted
jorgoz
Established Member
deleted
Ttrees
Iroko loco!
As you read from my posts I know very little about this, so wait for some confirmation from someone else first.
I suggest you check for continuity with a meter ...
No one has confirmed if a regular multimeter will do the job, but from my guess (remember I don't know what I'm talking about really) the meter Memzey has, looks possibly like a cheap one, I could be wrong.
Reason from my guess is that I was looking for the more expensive megohmmeters, @ around 35 quid on the bay for the cheapest one.
This was to get figures to do a motor insulation resistance test, as I thought my motor was possibly fried from stupidly stalling my saw being a numpty, and frying my poor Chinese VFD
This test is a similar to a regular continuity test which is probably where I would start if I were you.
As I said earlier in this thread, your motor looks to be dual voltage from the terminal box, although I'm still unsure.
You just backed up what would be my first suspicion and this would make me get a multimeter,
if that is indeed just a cheap as chips multimeter (clarification needed)
This link is for a motor insulation resistance test with the fancier type megger/megohmmeters and ohmmeters, but explains a continuity test clearly, aswell...
https://www.youtube.com/watch?v=FUjZwMMoltQ
Sorry I cant be of much help as I haven't done this yet
Awaiting others responses with interest
Thanks for taking piccys
Tom
I suggest you check for continuity with a meter ...
No one has confirmed if a regular multimeter will do the job, but from my guess (remember I don't know what I'm talking about really) the meter Memzey has, looks possibly like a cheap one, I could be wrong.
Reason from my guess is that I was looking for the more expensive megohmmeters, @ around 35 quid on the bay for the cheapest one.
This was to get figures to do a motor insulation resistance test, as I thought my motor was possibly fried from stupidly stalling my saw being a numpty, and frying my poor Chinese VFD
This test is a similar to a regular continuity test which is probably where I would start if I were you.
As I said earlier in this thread, your motor looks to be dual voltage from the terminal box, although I'm still unsure.
You just backed up what would be my first suspicion and this would make me get a multimeter,
if that is indeed just a cheap as chips multimeter (clarification needed)
This link is for a motor insulation resistance test with the fancier type megger/megohmmeters and ohmmeters, but explains a continuity test clearly, aswell...
https://www.youtube.com/watch?v=FUjZwMMoltQ
Sorry I cant be of much help as I haven't done this yet
Awaiting others responses with interest
Thanks for taking piccys
Tom
memzey
Established Member
Hi Jorgoz,
If you follow the link to my thread on the previous page you will see that first of all I had to identify where the star point was. I found it under some of the sheathing, at a point where three different windings came together. I can't be sure from looking at the photos but on your last picture there appear to be points at 2 o'clock, 8 o'clock and 10 o'clock either of which might be that point. I found that by poking it with a finger I could tell if there was a lump under the sheathing which would be indicative of three windings brazed together. I'd give that a go and see you can feel a likely suspect before cutting anything away. Once you have located the star point, everything else is pretty straight forward and written up in my earlier thread.
If you follow the link to my thread on the previous page you will see that first of all I had to identify where the star point was. I found it under some of the sheathing, at a point where three different windings came together. I can't be sure from looking at the photos but on your last picture there appear to be points at 2 o'clock, 8 o'clock and 10 o'clock either of which might be that point. I found that by poking it with a finger I could tell if there was a lump under the sheathing which would be indicative of three windings brazed together. I'd give that a go and see you can feel a likely suspect before cutting anything away. Once you have located the star point, everything else is pretty straight forward and written up in my earlier thread.
jorgoz
Established Member
deleted
memzey
Established Member
Hi Jorgoz - quick question; how many wires come out of the windings and into the junction box? It looks like it might be six in which case you can close the motor back up as it’s ready to be wired delta. You will need to identify the beginning and end of each tail though which is where the multimeter comes in handy.
jorgoz
Established Member
deleted
Myfordman
AKA 9Fingers
In which case there is no star point to find. isolate each of the 3 windings into pairs of wires that have continuity. measure the resistance of each pair and they should be all the same. Check there is no continuity between any wire and the body of the motor
label the ends A1 and B1 for one pair, A2 &B2 for another pair and A3 & B3 for the final one.
connect B1 to A2, B2 to A3 and B3 to A1. The motor is now connected in delta.
label the ends A1 and B1 for one pair, A2 &B2 for another pair and A3 & B3 for the final one.
connect B1 to A2, B2 to A3 and B3 to A1. The motor is now connected in delta.
Ttrees
Iroko loco!
There is a way to check for continuity with a lightbulb and a battery, not looked it up though,
you could probably get the bits from an old flashlight.
This might be more sensible for the frugal, in-case its best to get a megger to do the resistance test and not just the continuity test, so it'd save you a tenner buying the cheaper multimeter when the megger
can do that and more.
Tom
you could probably get the bits from an old flashlight.
This might be more sensible for the frugal, in-case its best to get a megger to do the resistance test and not just the continuity test, so it'd save you a tenner buying the cheaper multimeter when the megger
can do that and more.
Tom
