Hello ,

Ihave an Irem EX85 g xenon lamp power supply. The magnetic contactor has failed three times .Rather than replace it again is it possible (or wise) to simply connect the three phases together via a 500v/100a terminal connector and not use a contactor at all ? I don’t need it to be remotely operated and it can be switched on at the mains . Thanks , Jon

 

Explain how it failed?, i.e. coil burn out? contact failure?
Generally it is preferable to have a contactor when working with high power 3ph, O/L and rapid turn off capability.

 

Explain how it failed?, i.e. coil burn out? contact failure?
Generally it is preferable to have a contactor when working with high power 3ph, O/L and rapid turn off capability.

Hi ,
The first time I’m pretty sure the coil burnt out as it was making a loud buzzing sound .Second time there was a thud and then nothing . I can protect the unit with an RCD and hoping I can just directly connect the wires together bypassing the contactor ?

 

Generally for the reasons you state, an AC coil fails because of too low a coil voltage,
The best option is a DC coil version.

 

Hello ,

Ihave an Irem EX85 g xenon lamp power supply. The magnetic contactor has failed three times .Rather than replace it again is it possible (or wise) to simply connect the three phases together via a 500v/100a terminal connector and not use a contactor at all ? I don’t need it to be remotely operated and it can be switched on at the mains . Thanks , Jon

sure you can. What for the contactor is used? For remote control only?

 

sure you can. What for the contactor is used? For remote control only?

Yes, as far as I can see that’s what it’s intended for . It was designed to be controlled by automation, but this isn’t necessary for me , I can switch it on directly at the 230 v AC mains . Thanks

 

Hi
Ihave an Irem EX85 g xenon lamp power supply. The magnetic contactor has failed three times .Rather than replace it again is it possible (or wise) to simply connect the three phases together via a 500v/100a terminal connector and not use a contactor at all ? I don’t need it to be remotely operated and it can be switched on at the mains . Thanks

 

What is the power rating of the unit? Is it a permanently mounted unit?
This a NFPA regulations applicable in N.A.
https://www.c3controls.com/white-paper/how-to-size-a-disconnect-switch-for-your-project/

 

If the contactor coil failed by overheating and burning out, it may have been intended for only intermittent duty, or else the voltage was excessive. Or it may have been an AC coil operated on DC of the same voltage. The model number of the xenon lamp power supply does not tell me the current draw nor any start-up current. How many amps does the supply draw from the mains? And what voltage are the supply mains? AND what is the coil voltage in the application?

Indeed a contactor can often be replaced by a terminal block, a better choice usually will be a suitably rated switch.

 

If you make changes to your own equipment, in the event of a mishap, it is on you, but if you want to be safe, or others are using it, there are regulations for disconnect in permanently mounted equipment etc
Per NFPA70 & NFPA79.

 

The fact is that we know nothing about the application, and if we did not research the model number, we know nothing about the load. In addition, we know nothing about the power that the TS used to operate the contactor. So every response is based on a guess of some kind. Including rules that may not apply at all.

 

@Kinoton Are you in the UK? I have been out of the loop there for many decades now, so I would suggest checking current/local regs as to what you have and what is required.
Normally not a very good or safe idea to use the main breaker as a switch.

 

There are available multi-pole "disconnect " switches in a variety of current ratings. So that is another option that would allow switching the power supply off at it's location. That might be inconvenient, though. We are told it is a xenon lamp power supply, which might include the starting circuit, or maybe not. WE are not even told about the power connection.
Presently I recommend replacing that contactor with an equivalent capacity disconnect switch. Then you have safe local control.

 

Ihave an Irem EX85 g xenon lamp power supply. The magnetic contactor has failed three times .Rather than replace it again is it possible (or wise) to simply connect the three phases together via a 500v/100a terminal connector and not use a contactor at all ? I don’t need it to be remotely operated and it can be switched on at the mains . Thanks , Jon

I would be interested in why the contactor coil failed 3 times?, if you just replaced the coil, instead of the whole contactor, one of the symptoms of buzzing, apart from too low coil voltage, is when one of the contactor armature shading rings have opened.
Rare, but does exist.

 

In my experience, buzzing, chattering relays (that were working) is mostly due to contaminants preventing full armature action. What’s the environment?

 

One reason I always use DC for contactor/relay coils also solenoids where at all possible.

 

It should be very clear that the failure is most likely due to a mismatch between the coil design voltage and the applied voltage. The TS never mentioned what the connection arrangement was , nor what the specified coil voltage was. So without checking the coil gets connected to the supply voltage, much greater than the specified coil voltage, and the device operates for a while. Then the coil "mysteriously burns out", and so an exact replacement is installed and that one fails as well. The same failure has happened on larger air compressors, where the 120 volt contactor coil was wired across two legs of the 240 volt supply. One day of operation was all it took.
So the very first thing to check will be to verify that the coil voltage applied matches the coil voltage required. Reading those installation instructions is often very important.