Furnas switches

[Warren Lake]

I think one heater went down on the third switch to the right, left side of it first phase these being 220 three phase. Anyone know if this company still exists and parts can be had for the switch. Like to keep it all original if possible. I did some looking a few days ago and seems only used stuff around but asking one supplier now that has old stock of Danfoss before they were gone and might be able to find more. The side shot is of the first left hand switch but pretty sure they are the same.


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[Thomas McCurnin]

Nothing wrong with used parts, so long as if they don't work or are not as described, the seller agrees to accept returns. I saw one for $90 on eBay. I saw this listing without a price: https://www.electrical.com/Products/Motor-Control-Siemens/11DB3B

[Warren Lake]

thanks think I found that and some other and had it saved. Im not sure if the company is gone at this point. I have to ask if we have surplus places around as well. LIke to replace with the original parts and not and not change out the switch if possible

[Bill Dufour]

Siemens bought out Furnas in 1996? I think you can buy parts to fit that are now labeled Siemens.
There should be a label in the box about what the heater number means as far as amps.
Bill D

[Warren Lake]

thanks bill ill take a look. so a heater has a value pre set amount unlike an overload where you can dial in the amps on other magnetic starters. There is also a coil and magnet thing in those that sucks in to stay on. My caveman way of describing it. Have the machine many years and its from a friend who had it a long time before and from new. Likely in the 60's. they are the nicest machines like being a second owner well cared for car.

[Bill Dufour]

Coil and magnet is a contactor.
Overloads can be modern adjustable or old school heaters that are rated for a certain amp load.
If you can not find a number just figure out the FLA on that overload and buy based off that. It is entirely possible the heater coils are way too big and do not really provide any protection. But, since one burned out, they are probably correct or even too small for the current load.
You can jump the bad heater with some small bare copper wire and verify everything is correct downstream. Make sure the wire runs cool.
I have used a three phase contactor for single phase and only bought one heater. Permanent jumper on the other one. Not completely safe but good enough for me.
Bill D

[Jim Koepke]

I've had luck finding replacement parts for discontinued equipment from these folks > https://www.supplyhouse.com

jtk

[Bill Howatt]

Coil and magnet is a contactor....
I have used a three phase contactor for single phase and only bought one heater. Permanent jumper on the other one. Not completely safe but good enough for me.
Bill D

I think the better way to use it for single phase is to run the unused heater in series with an active heater. This way the "device" heats up as designed with 3 heaters and does not run cooler because one of the heaters is not active.

[Bill George]

Is it actual 3 phase? If so you can get by for overload purposes just with 2 OL heaters. Why? If its three phase it will be drawing the same amperes on at least two of the three phases and for motor overload protection thats all you need. For shorts and grounds you have the C/B or fuses.

[Bill Dufour]

Is it actual 3 phase? If so you can get by for overload purposes just with 2 OL heaters. Why? If its three phase it will be drawing the same amperes on at least two of the three phases and for motor overload protection thats all you need. For shorts and grounds you have the C/B or fuses.

Yes, but if the cord between the motor and the overloads gets cut and shorts to ground on the one line not on the heaters there is no protection. If it is a full short the fuses will handle it. If it is just a shorted winding it may not blow a fuse.
BillD

[Bill George]

Yes, but if the cord between the motor and the overloads gets cut and shorts to ground on the one line not on the heaters there is no protection. If it is a full short the fuses will handle it. If it is just a shorted winding it may not blow a fuse.
BillD

The circuit breaker will protect the wiring in a short or grounded wire condition. If its a shorted winding the phase to phase current draw is still present. The OL is there to protect the motor and take it off line before it burns out in case the motor load is to great.

By shorted your saying phase to phase, in that case one heater will still be active, correct? Grounded one phase the circuit over current protection will take it off by tripping the C/B or blowing a fuse. Then if only one fuse is blown the other two legs still connected to the motor, one has a OL heater, correct?

[Bill Dufour]

Then problem is if the coil is shorted to ground. It may have enough coil windings left that there is enough resistance not to blow the fuse. But that could be enough to burn the rest of the motor.
Bill D

[Warren Lake]

thanks most of that is above my understanding electrician brought a guy who does all their machine service. He thinks the motor is okay and he didnt see the same issue in the Roto the other electrician did. They didnt have much time. I said if I can id like to have the same switch. He said he doesnt like the way its wired one jumping to the other from left to left and explained why said he would normally wire it in a different way. It was left that I take some close ups of the switch and what each motor is on the machine (3) and send him that info then will go from there.

[Bill George]

Then problem is if the coil is shorted to ground. It may have enough coil windings left that there is enough resistance not to blow the fuse. But that could be enough to burn the rest of the motor.
Bill D

If the motor has a shorted winding or its grounded... its toast. With a direct short to ground the overload heater could be burnt out anyway. If your going to rewind the motor instead of replacement... the entire motor gets rewound, No halfway repairs.

When wiring a motor feeder circuit there are two requirements: First overloading the motor with too much of a load hence motor thermal overload protection accomplished with the motor starter overload devices either properly sized heaters or electronic protection. As on a saw, you over load by overfeeding the stock and jam it up, it trips the OL. A 3 phase motor has 3 hot wires as you know, but its phase to phase not to ground. So all three phases will be passing current.
even with just two OLs in the circuit, one is all you need to drop out the starter coil as they are wired in series. But Code requires 3 OL or thermal protection devices, one for each phase. Not always that way but it was changed years ago.

Second protection required is over current for the motor feeder / branch circuit to protect the wiring from a short circuit and ground fault condition.

This is all covered by the NEC Article 430.

[Warren Lake]

here is the side of the switch and then under the cover thanks for mentioning that. Id still like to be stubborn and find the same replacement so have sent some feelers out up here.

508879508880

[Bill George]

That company Furnas has been around forever and I have worked on in the past. A old company that does motor controls probably has what you need in the back room. Ebay may also be a good source and you only need one heater / thermal OL heater that is, it should be marked with the part number or size.

[Warren Lake]

are there part numbers on the heaters ive not taken these apart before but can do this one here. Put out feelers to a few people one on holidays one will hear back few others not around parts anymore then there are some surplus dealers;. If non pans out then will have to assimulate and change the whole thing out to magnetic

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[Brian Elfert]

It looks like you can still buy the entire assembly. Ebay has at least one seller of a used Furnas 11DB3B.

[Warren Lake]

so if I use that part number does that mean the heater coil value is correct as they have different number heater coils Ive seen 28 listed and 32 but they didnt put values on them ill take one apart here and see if there is a number anywhere

thanks

[Bill George]

It looks like you can still buy the entire assembly. Ebay has at least one seller of a used Furnas 11DB3B.

That is for the entire starter, all he needs is the correct OL heater element which is sold separate. Replacement is about a 5 minute job.

[Warren Lake]

first electrician said dont run stuff the man factured phase is too high and likelyi took the heater coil out. second electrician measured phase to phase instead of phase to ground. He got 251 volts on the roto generated leg and said dont worry plus one other bright guy here said same only 5 percent over. then a super bright friend I had mentioned the generated phase being high sent me this.

For you guys that have huge knowledge of all this just passing this on from a friend. It shows what I was told by first one was wrong or at least the dont run the shop thing the roto took out the heater is likely wrong or maybe it did if it did the switch heater still has over 60 years on it. all three same furnas stuff and same age so even if some dont like them or say they are cheap and most seem to they did perform for a long life have had past many magnetic starters faill worst the compressor that after 35 years the contactor welded itself in the on position and the compresser did not turn off after reachiung high shut off and went way past

https://www.electram.com/1/different-voltage-on-line-3-phase-converter.php

[Bill George]

[QUOTE=Warren Lake;3278569]so if I use that part number does that mean the heater coil value is correct as they have different number heater coils Ive seen 28 listed and 32 but they didnt put values on them ill take one apart here and see if there is a number anywhere

thanks[/QUOTE[/I]

If you turn the power off and remove the old one it has a number stamped on it someplace. Usually if your eyes are good you can read it when installed, they should all be the same. When I had my old roto phase converter on my Emco Super 11 Lathe I never paid a lot of attention to the heaters as they were factory installed.

[Warren Lake]

Bill im 67 nothing is good:) my mom said many years ago after 40 you will see everything changes. Are you kidding.

Actually im okay but for sure reading glasses are a must. Will take it apart and yeah turn the power off first thanks

[Bill George]

Bill im 67 nothing is good:) my mom said many years ago after 40 you will see everything changes. Are you kidding.

Actually im okay but for sure reading glasses are a must. Will take it apart and yeah turn the power off first thanks

BTW your first electrician ??? did not have a clue, 3 phase is measured phase to phase for motors never to ground! We did have in the plant 277 volt lighting circuits that were 277 to neutral off a 480 volt 3 phase but that was it. I am going on 81, glasses needed for close up stuff for sure and readers work just fine. I do have bifocals if needed.

On a Rotary phase converter its normal to have one phase higher. I built mine and had it pretty well balanced as I had a bunch of old Run capacitors to swap in and out as needed to balance.

[Warren Lake]

Hi Bill

I see people in all trades with different back grounds At one point had an austrian electrician apprenticed in his teens and was nearly 80. In a lifetime of work he never saw a roto, looked at the manual a few mintues said okay I get what is going on. Hes well retired now so dont bug him. still find the same with trades the one old cabinetmaker of all the older ones ive known kjew more than the others. Better apprenticeship in a town that had been bombed so in his teens making gothic church windows and six inch thick doors then in canada started at the bottom to running the jobs for a company with over 400 people. He was gifted as a teen but really he was in the right place about every time to see and learn more.

Appreciate your knowledge I will take that part out later just doing five things at once, reading glasses on.

I did email that company to say thanks for the article and they said they mostly make digital stuff now cheaper to run and better so guess more to learn depends on cost and other things as well.

[Rollie Meyers]

Is it actual 3 phase? If so you can get by for overload purposes just with 2 OL heaters. Why? If its three phase it will be drawing the same amperes on at least two of the three phases and for motor overload protection thats all you need. For shorts and grounds you have the C/B or fuses.

3 OL's are required by code for 3 phase.

[Warren Lake]

I guess I could take the heater out of the first switch as they are likely the same value. First switch is a fan. Havent had time to get back to it yet.

[Bill George]

3 OL's are required by code for 3 phase.

See Post #14 and I am old enough to remember that was not always the case....

[Bill Dufour]

I would assume the fan heaters are lower rated then the heaters for big motors.
Bill D

[Warren Lake]

Hi I haven't got there yet but will yes on that statement the two motors fan and power rise are .5 HP which is not exactly accurate as the raise motor says .34 HP I think will check. The main motor that runs the 309" belt is 4 HP

that is interesting as this machine ran for 30 years approx on a very simple 3 HP Delta TMe roto phase. Three or four years after I purchased the machine the lady called and asked me to come and pick up the roto. I did and ran three machines off it just fine even another 4 HP on the mortise machine. No fancy circuits in it just some caps. Later changed out that Roto for a 10HP same brand to be able to run up to 10 HP machines.

Ill get to the heater in the next day or two. thanks for all thoughts so far. Just haven't had time to focus

Of interest here is the second electrician to look at the switch looked at the power up and down switch. He said it made no sense needed more wires then said unless the table fall lis by gravity i said no but then thinking aboiut it next days im now pretty sure he is correct. I had pulled the motor back from the gear up and down, should not have done that but same time maybe a reason as well. I wanted to know the motor would spin free. When I pulled the motor out the power table fell right away and I just grabbed a block to support it.

This one aspect of these machines is why ill always have a stroke sander because you can drop your table you can put whole cabinets into the sander,. you can also have rails and hang off the table depending on the sander rails and you can also take bars out of the table and put a cabinet in there when you put the bars back in. Then you can sand a cabinet just the same but not have to drop the power table down.

here is the sales thing back side. It means nothing if a motor is replaced. This motor on the power rise says Bulgaria on it so either it was replaced or it was their source when this was built in Italy. Or would an Italian machine only have Italian motors. All my other ones all the motors are Italian. So listed below says .5 HP for power table if im reading correctly.




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[Bill George]

Those heaters should be replaced with the same one that came with it for that motor. They are sized on amps not Hp and if its been running for years don't change things. I am assuming your in the US?

[Warren Lake]

just north of toronto ontario