Low and High Voltage in same Raceway

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rburns001

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We have an independant electrical contractor coming to discuss doing an assesment on our 4160v. power. My first question is, Have you heard of a new O.S.H.A. ruling stating that we will need a third party assesment or inspection to determine if our flashsuits and high voltage gloves are sufficient for the voltage we deal with?
My second question is in response to a manufaturer who will not build a termination box for a 4160v. motor because we require a 120v. heater strip inside the box to energize whenever the motor is not running. The response was that thier engineers say this is in violation of the code, "you cannot have different voltages in the same termination box". Could you refer me to any articles that state I can put a 120v heater element in the same box as my 4160v. motor leads. Thank You, Robert Burns
 
Re: Low and High Voltage in same Raceway

Any time that you have a heater that comes on when the motor shuts down will need an external source of voltage. We have done this many times in industry. What I would do for safety is to put a red tag on the terminal box, stating that their is a external source of voltage,120 volts being fed from Panel X, Circuit X. When I say tag, I do not mean a paper tag, we would put a plastic tag, that will stay in place.
Now to the OSHA ruling on High Voltage Equipment, and having the proper PPE protection. It all depends on the expertise that you may have to satisfy the OSHA standards. If you do not have this knowledge, then I would suggest that you get someone.
If you have a contact with the Bussman Fuse Company, they may come in and help you out with their expertise.
 
Re: Low and High Voltage in same Raceway

I like Fiebels idea, and there are self adhesive labels that you can get that state "caution energized by more than one source of power". Its not the 4160 that will get you it will be the 120V.

If the 120V is fed from the motor controller, then it will be off when the motor controller power is off. If from an external source, then run the 120v thru a aux contact on the motor controller disconnect, Part VI of Art 430 covers control circuits for your reference
 
Re: Low and High Voltage in same Raceway

Thank You for your response. The article 300.3(c)(2)(d) should satisfy our vendor in order to make the termination box.
We do have tags on our termination boxes in the field and on our switchgear and I know that our flashsuits, gloves, and mats are rated for 20,000 volts, and they are inspected by a third party inspection company once a year. What I would like to know is, has anyone been told they have to have to have an assesment done at thier plant or facility? i have been told that o.s.h.a. requires that we have a third party come in and inspect our high voltage safety equipment to establish if it is efficient. Thanks again for all of your help. Robert Burns
 
Re: Low and High Voltage in same Raceway

The high voltage motors that I have worked on had second termination box for the heater if there was a heater. Often there was a third termination box for the RTDs.
Don
 
Re: Low and High Voltage in same Raceway

Most of our 4160v. motors have a seperate box for the motor heaters. This particular application is for one of our motors that also has a heat strip in the motor termination box. We find this necessary in Houston. ( You will notice that I used the term "motor termination box") a new term we have to use.

[ January 28, 2004, 01:01 PM: Message edited by: rburns001 ]
 
Re: Low and High Voltage in same Raceway

I was reading thru 300.3. When I got to the very end of it, there is a paragraph that says, the conductors have to be shielded to be in the same enclosure.
 
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