3 phase TS Motor Change - Thermal Protection Still Good?

[Matt Hutchinson]

So, a few years ago I purchased a TS and jointer form a high school shop. I knew they were 3 phase, and that they needed a little tlc. To make a long story short, the motors were a different voltage than I can use, 200v.

I already killed the jointer motor by running it at 230v, and instead of killing the ts motor I found a used 3 ph, 230v replacement.

Here's the question:
The TS has thermal overload protection, y'know, 3 "coils" in the box on the back of the saw. Since the new motor is 230v, and the machine is set up to run on 200-208v, does the thermal protection need to be changed/adjusted as well? Horsepower between the motors is the same.

Thanks!

Hutch

[David Kumm]

Look at FLA on motor and compare to heater chart inside the enclosure. The new motor probably pulls less amps than the old but comparing motor plates will tell you. Dave

[Kirk Poore]

Look at FLA on motor and compare to heater chart inside the enclosure. The new motor probably pulls less amps than the old but comparing motor plates will tell you. Dave

Yes, they need to be changed out. As David says, there should be a chart in the enclosure that, when matched with FLA on your motor plate, should tell you which ones to get. I've bought heaters for $6-$12 apiece, so that will give you a starting point on price.

Kirk

[Chip Lindley]

Matt, to add to the info already provided, your TS will run with the existing "heaters" but they will not provide overload protection for your new motor. Heaters sized for 200v have a larger amperage rating than those needed for a 230v motor. For testing purposes you will be ok. But DO change to heaters sized for your motor's amperage.

For the record, there is a market for 200v motors among those with commercial 3-phase power. Instead of frying 'em, sell 'em! At least you can probably recoup enough to pay for a new set of heaters.

[Matt Hutchinson]

Thanks guys! I will check the chart and purchase the necessary parts. I may have to run a few boards through it prior to putting the proper changes in place, cuz I have a job that a customer needs ASAP. But as soon as I get 'em, I'll install 'em.

Hutch

[Matt Hutchinson]

Here's something interesting. It appears that the heaters already installed are undersized for the 200v motor, and that they are perfect for the 230v motor. Here's what the chart reads:

Full Mo. Min.|| Load Amps Max. || Heater Code No. || Max. Rat. of Prot. Device Fu. == Bkr.
7.04..................7.74 ....................E52 ........................ 30 == 30


E52 is what's currently installed, and the 200v motor is rated at 7.8 amps.

Also, one more question. The motor on the jointer has no thermal overload protection. It was super hot when running for only 10 min. Because the TS has the thermal protection, if it gets hot will it shut down before any damage occurs? Thanks

[David Kumm]

Matt, The heaters don't allow excessive amps to be drawn but if you have a motor or winding problem plenty can go wrong without the heaters kicking out. Motors run a long time should get hot to the touch but not super hot. You can take a motor in to be tested for less than $20 and find out what you have. Sometimes the rotor and stator are misaligned a little. You can see that if you pull the motor apart but I would find a motor shop and have it looked at. Dave