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Thermal cutout / fuse replacement for old Hardinge Lathe
- Thread starter mcbassin
- Start date
mcbassin
New member
Larry, Thank you for the response, This box (pictured) is obviously different than mine. I will take pics of my actual box. The devices I want to replace are some sort of overload protection. They are located this same area in my box. I think they might be a slow blow fuseable link? Anyway, On one of my speed adjustment legs, I have a lower voltage so the motor
will not spin unless I jumper this fuse.
Make sense?
mcbassin
New member
I isolated the lower voltage problem to this thermal cutout. It has perfect voltage on the incoming side but low voltage coming out. Am I missing something?
The problem appears to be the fuse. I suspect it was damaged but not completely blown when I had the wiring polarity backwards when I installed the machine. I ran the
RPMS down but it wouldn't return, I feel like there was too great of a load on the speed adjustment motor protection.
dalmatiangirl61
Active member
Please provide a closer pic of the actual part in question, and any info you can see on it, with that info I can look thru my inventory for a replacement. If its just a heater it would need a new element.
mcbassin
New member
dalmatiangirl61
Active member
A heater is part of an overload device, they can burn out, but getting partial power sounds "funny". Your pics are coming out too small, and I need up closer pic to tell what I'm looking at, and any data that is on it.
mcbassin
New member
TDegenhart
New member
As pointed out, that is an overload relay. Remove your jumper and under the screws should be heating element that goes down into the relay cavity. If there is none or the heater is burnt out, then that is your problem. Your motor is running single phase. Take one of the heaters out of one of the adjacent relays. You will need one like it.
Tom
Tom
mcbassin
New member
Thanks Tom,
When I think of a relay, I think of a contact type of device. I’m not electrical expert at all, obviously....
Are these heaters available still? I thought that this technology was antiquated. That was the reason I started this thread to fin a suitable replacement of modern circuit breaker.
dalmatiangirl61
Active member
Yes, heaters are still available, yes they are antiquated, just like the lathe. Remove old one, take it to electrical supply house, match up numbers to a new one.
Edit: OP says he has "lower voltage" going thru that heater, my experience is they blow and you get no voltage, anyone else find his problem odd?
Edit again: Yes, a heater is basically a fusible link, you just need to remove the element part, it has numbers on the tabs, do not remove whole plastic assembly.
Edit again: Did you put the green jumper in, or is that how you got it?
Edit: OP says he has "lower voltage" going thru that heater, my experience is they blow and you get no voltage, anyone else find his problem odd?
Edit again: Yes, a heater is basically a fusible link, you just need to remove the element part, it has numbers on the tabs, do not remove whole plastic assembly.
Edit again: Did you put the green jumper in, or is that how you got it?
mcbassin
New member
I put the the green jumper in to confirm that it would work without the fuseable link. What supply house do you recommend? Grainger? Allied...? Mouser?
Yes I find it odd but the wiring diagram is from 1963... It's antiquated for sure...
dalmatiangirl61
Active member
Grainger and McMaster should both carry them, barring any supply chain issues.... If you have an electrical supply house locally that carries Square D stuff they will most likely have them or can get them.
mcbassin
New member
SQUARE D Thermal Unit, 0.53 to 0.63 Full Load Amps, For Use With Square D NEMA Motor Starters 00, 0, 1 - 1H598'|'B0.71 - Grainger
I think this is very close Amp rating but a little different design.
dalmatiangirl61
Active member
Did you get info off the old one, or one of the good ones? I'm smart enough to change same for same, cannot comment on different ratings or styles.
Doozer
Active member
An overload "heater" is NOT like a fuseable link.
An overload "heater" is a device with contacts.
There are a few types. There are ones with a
bimetalic strip that opens the contacts. Think
auto reset type. There is the type that melt a
bit of lead/solder and a spring lets the contacts
open. Think push to reset type.
-Doozer
An overload "heater" is a device with contacts.
There are a few types. There are ones with a
bimetalic strip that opens the contacts. Think
auto reset type. There is the type that melt a
bit of lead/solder and a spring lets the contacts
open. Think push to reset type.
-Doozer
