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X-ray service entrance, doesn't meet manufacturers specs but local code official pass

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Pioneer Tom

Member
Joined
Nov 28, 2013
Messages
11
Location
NJ
I signed a contract with an electrical contractor to install a dedicated service for an X-ray. The contractor claimed to have done many x ray installations, he filled out the permit as a 100 amp electrical service and told me to take it down town and pay for the permit. Initially he installed #2 aluminum for this 90 foot run, it failed, inspector asked for spec sheet on X-ray machine, contractor replaced with #1 aluminum without consulting specs, specs require 2/0 copper only and a 100 Amp disconnect ( this is required by essentially every x-ray manufacturer as it has to do with most modern machines change the AC to DC and in doing so you have hundreds of amps flowing for a few milliseconds each time the rectifyer diodes open to feed a capacitor bank, somehow induction in the line is the other explaination of the oversize [see ampacity tables] wire and additionally aluminum apparenty produces harmonic chatter that disturbs the high frequency inverter that takes the DC to a high frequency AC that allows the use of a much smaller transformer than was formerly used to produce the 125 kilovolts to the X-ray tube), install failed to pass second time, contractor appealed to manufacturer to approve his install, manufacturer refused and said warranty would be voided and x-ray machine would probably need to be derated if installed, install failed to pass 3rd time, contractor threatened to appeal code officials decision ( which contractor had done successfully with this inspector in past), code official folded and passed install. Now I have a useless installation that the contractor is demanding payment on. Because the code official passed it I will now have to hire an expert witness and take time out from work myself to go to court numerous times if he presses to be paid for his useless installation. I need to keep this inspector happy in my town but he's put me in a mess by passing this (he passed it after 3 months on the 27th). What can I do. Can I appeal the inspectors decision? Again the permit app only mentions only a 100 amp service but the contract between myself and the contractor mentions the X-ray machine. HELP PLEASE.

Sincerely; Pioneer Tom.
 
It sounds like your contract was not specific enough and he did not bid 2/0 copper.

At this point there is a good chance the wrong pipe was installed too.

The contractor probably has a better case than you.

Read your scope of work again and see if it says 2/0 copper (or copper at all). Otherwise a 100a service can easily be construed as #1 al. (the #2 would only work on residential)
 
From the 2011 NEC;

110.3(B) Installation and Use. Listed or labeled equipment

shall be installed and used in accordance with any instructions

included in the listing or labeling.

Clearly the inspector should not have passed the install described.
 
The way I understand it, the permit just said "100 amp service".

If the X-ray install was on the permit, I might agree.

This really sounds like a poorly written contract and a questionable spec from the manufacturer.

If you actually read the intsructions for a Dayton motor they tell you the circuit needs to be sized for LRA. You end up with some ridiculous wire sizes like 8 ga on a 1/2 hp motor if it is 50 feet away.
 
I questioned the specs but they are real as all 5 manufacturers I checked with had same with minor variations. They can be a great distraction. I appreciate the comments. Is the standard that somehow the customer is supposed to know how to design the installation the contractor is hired to do. It may be the reality but it makes no logical sense. Can I asked the inspector to reverse his decision and update the permit to mention for an X-ray? So then he has a firmer basis to fail it? Is there any other solution.
 
Should a permit be granted to add a second service to a unit without stating what the service is to be used for?
 
We wouldn't approve a service without knowing what the connected load will be. The X-ray machine would be on the permit.

You should talk to the inspector before going over his head but you can't accept this. The work must be redone with a different contractor and new permit.
 
I plan to talk to him Monday morning and am just trying to find a basis to ask for the change. When I paid for the permit the electricial had filled out I verbally said it was for a new X ray but the contractor didn't put it down.
 
Chris Kennedy answered your question in post #3

From the 2011 NEC;110.3(B) Installation and Use. Listed or labeled equipment

shall be installed and used in accordance with any instructions

included in the listing or labeling.

Clearly the inspector should not have passed the install described.
Click to expand...
Obviously the inspector has an issue here. He correctly failed the work because it went against the installation instructions. Neither the work nor the instructions have changed; so no matter what the inspector has approved, the violation exists.

Who holds the permit?
 
Last edited by a moderator:
Pioneer Tom said:
When I paid for the permit the electricial had filled out I verbally said it was for a new X ray but the contractor didn't put it down.
Click to expand...
So permit was for new service only? Permit for the actual x-ray equipment is to come later with equipment install?

I agree with Ice, here also I would have to submit a load calc with the service permit app. Any chance you could link us to the equipment specs? X-ray equipment have their own section in the NEC (660) and the calc would be dependent on the specific type of equipment.
 
The permit has work site, owner in fee, contractor but nothing saying the permit is pulled by a specific individual. The attached E. subcode tech section is stampted and signed by the electrical contractor, no plans required is checked. In the very small space for description " adding additional meter & main breaker for 100 amp service. I hand carried to building office paid the fee and verbally said it was for an x-ray machine.
 
Load info submitted to utility. Manufacturer says 30kW HF generator and 2/0 AWG copper for a run of 90 feet. I'm sorry I'm not sophisticated enough to set up a link.
 
It is a diagnostic machine( max of 6 seconds typically less than a tenth of a second) it is 300 MA, 125 KVP machine so not a dental machine and not a therapeutic (continous load) machine.
 
Here is the issue you have. Art 230 does not specifically address a service built just for the equipment you have. Arts 660 and 220 address branch circuit and feeder calcs for your equipment. Long story short a service with smaller conductors than the feeder conductors in the manufactures specs could indeed be code compliant.

Check your notifications, I'm sending you my mobile number. I really need to see the specs for your machine to be of any further help.
 
Been having trouble with site loosing my posts. In 660 in my 2003 handbook there is a FPN that say's usually manufacturer's specs are followed for voltage regulation reasons and in NJ there is NJ AC 5:23-3.6 also indicate manufacturers specs be followed. I of course am not an expert in reading code but the passages seem pertinent.
 
Does NJ have a state Health Department to inspect & approve this X-Ray machine install?

In this state, there is a requirement to inspect all X-Ray machine installs, including the

lead lined walls, ..doors, etc.

.
 
globe trekker said:
Does NJ have a state Health Department to inspect & approve this X-Ray machine install?
Click to expand...
If used for health care then 517.73(A)(1) would apply, not a game changer as it reads the same as 660.6(A).

Never mind, just checked your profile, yours would be a 660 install.
 
I would suggest you contact the inspector. Ask first for chapter and verse that supported his change of position to approve the install.

Than I would ask for what in the NEC supports his position not to follow the manufactures specification?
 
The work flow was to be install power, local code inspect, install machine that needs to be caliberated to the power under load, local code inspect, then state x-ray inspect.
 
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