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Moving Motor Termination Box to Top of Motor with custom duct

Moving Motor Termination Box to Top of Motor with custom duct

(OP)
I have a situation where I need to move the motor termination box to the top of the motor, because of clearance issues. The motors are 480V, 200HP, TEFC. I contacted a motor shop and they can make a duct from the side of the motor to the top of the motor where I can re-attach the motor termination box. My question is the motor termination box considered pat of the electrical motor? I am wondering if I will run into a UL issue by doing this?

Thanks

RE: Moving Motor Termination Box to Top of Motor with custom duct

Howdy,
Is the motor shop certified to do this type of work? If not you can almost certainly loose the UL listing on the motor. How old are the motors (ie are they still on warranty, and if so is this a concern to you)?
Is it possible to do a 180 on the stator case? That will put the J-Box on the other side (ie make a F2 out of an F1 motor). This is an easy thing to do, any motor shop could do this and not impede your UL listing.

GG


"I have not failed. I've just found 10,000 ways that won't work." Thomas Alva Edison (1847-1931)

RE: Moving Motor Termination Box to Top of Motor with custom duct

Underwriters Laboratories has nothing to do with where you re-locate a termination/connection box on a Totally Enclosed Fan Cooled Motor.
If the motor was/is an "explosion proof" motor than -no-. You would not be able to relocate the box.
The connection box is not considered a "part" of the motor. It's often left hanging with the rest of the connection leads
[on site] when removed from service for maintenance. In some instances, there is no connection box at the motor, and leads are fed
directly into the apparatus via a suitable conduit, duct/raceway.

Perhaps others will chime in with there knowledge on the subject.

John

RE: Moving Motor Termination Box to Top of Motor with custom duct

I would turn the box so that the threaded hub is pointing up. Then install a rigid conduit nipple with an oversized condulet on the top.
The condulet can form your new "J" box.
The conduit may be bent as needed.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Moving Motor Termination Box to Top of Motor with custom duct

I do not agree, dArsonval. The junction box that is part of the motor is also part of the approval. This will include the volume and the method of mounting to the motor and the thickness of the walls.
All components of a wiring system must be approved.
ksavoie1: The local inspector may be able to help.
Some inspection jurisdictions have provision for a one time inspection and approval on the jobsite.
I have used this provision when a customer brought in machines from offshore that did not have UL approval.
I made application for each individual machine. The inspector inspected each machine and either passed it or, in some instances, demanded some minor modification before approving the machine.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Moving Motor Termination Box to Top of Motor with custom duct

(OP)
From my research TEFC motors are not UL listed, only TEFC Explosion-Proof are UL Listed. My motor is NOT "Explosion-Proof" so I should not run into any UL issues.

RE: Moving Motor Termination Box to Top of Motor with custom duct

Quote (OP)

From my research TEFC motors are not UL listed, only TEFC Explosion-Proof are UL Listed.
All electrical equipment must be approved by a recognized agency. UL is not the only recognized agency (CSA and others).
The comments in regards to UL apply as well to all approving agencies.
Your approval may not be UL but whatever the approval, it will probably be voided in the same way as the UL approval would be.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Moving Motor Termination Box to Top of Motor with custom duct

You might be able to meet the electrical requirements, as discussed, but have you considered the box location (mass and stiffness)may create a high vibration issue?

Walt

RE: Moving Motor Termination Box to Top of Motor with custom duct

fwiw, your conclusion ksavoie1 is consistent with what I would conclude for my particular situation (US power plant).

We would be comfortable to make modifications like this for many motors (subject to evaluation … does it interfere with cooling, are there unique application considerations, etc) as long as it is not an explosionproof. The only motors in our plant that have a UL requirements (and UL labelplate attached) are those that are explosionproof.

=====================================
(2B)+(2B)' ?

RE: Moving Motor Termination Box to Top of Motor with custom duct

From the Canadian Code;
"Electrical equipment used in electrical installations within the jurisdiction of the inspection department shall
be approved and shall be of a kind or type and rating approved for the specific purpose for which it is to
be employed."
Is there anything similar in the NEC?
This rule would prohibit a field fabricated duct in Canada unless some type of approval was obtained.
Substitute "Approval" for "UL". Do not assume that the absence of a UL label-plate implies the absence of an approval.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Moving Motor Termination Box to Top of Motor with custom duct

NEC does not apply to utility power plants in US (NESC does apply). For our plant under the NESC, there is no general requirement that all motors be listed.

I'll let someone else respond about NEC.

=====================================
(2B)+(2B)' ?

RE: Moving Motor Termination Box to Top of Motor with custom duct

Thanks for the clarification Pete.
However is the motor in question in a power plant?
Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Moving Motor Termination Box to Top of Motor with custom duct

(OP)
Actually these motors will be in a distillery. We talked with a GE factory Rep and he said since it is not A CL1 DIV2 Motor and as long as we do not drill into or open the motor we can move the termination box as long as it as long as a qualified motor shop does the work.

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