Optional Generator Back Up System for Industrial Manufacturing

scnkapc

scnkapc

Member
Location
Northern Kentucky
Where can I find how many seconds are required for the transfer of power from utility to generator when the ATS is activated?
Inspector is requiring a 10 second max for this transfer of power.
 
For Optional Standby (article 702) there is max, it could be a manual switch.
 
Really need to be clear as to which type of standby power or generator purpose, The definition or scope really changes everything:

Article 700 Emergency System in 700.12 has the requirement of "within 10 Seconds" for Emergency power
700.1 Scope
This article applies to the electrical safety of the installation, operation, and maintenance of emergency systems consisting of circuits and equipment intended to supply, distribute, and control electricity for illumination, power, or both, to required facilities when the normal electrical supply or system is interrupted.


701 Legally required Standby system in 701.12 has a requirement of "not to exceed 60 seconds"

701.1 Scope
The provisions of this article apply to the electrical safety of the installation, operation, and maintenance of legally required standby systems consisting of circuits and equipment intended to supply, distribute, and control electricity to required facilities for illumination or power, or both, when the normal electrical supply or system is interrupted.

702 Optional standby systems have no such time requirement.

702.1 Scope
The provisions of this article apply to the installation and operation of optional standby systems.

The systems covered by this article consist of those that are permanently installed in their entirety, including prime movers, and those that are arranged for a connection to a premises wiring system from a portable alternate power supply..

Many times a HO wants an "emergency generator" but in reality it is an optional standby generator even though they want it because of medical devices or refrigeration.
If your inspector is asking for a "10 seconds" requirement does your generator purpose meet the requirements of article 700? And not an optional standby system article 702?
 
Fred B said:
Many times a HO wants an "emergency generator" but in reality it is an optional standby generator even though they want it because of medical devices or refrigeration.
If your inspector is asking for a "10 seconds" requirement does your generator purpose meet the requirements of article 700? And not an optional standby system article 702?
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Transfer time does not define the NEC article for the installation.
It is totally possible to have an Optional Standby system with a 10 sec transfer time if that is what the customer wants.
 
Jim,
This falls under 702 Optional Standby Generator. It is being used as a backup for emergency lighting and fire alarm. Not for manufacturing or processing. 702 does not say anything about the delay in seconds for transfer of power. Is this a fire code or other NFPA requirements for the 10 second rule? This is not for healthcare.
 
scnkapc said:
Jim,
This falls under 702 Optional Standby Generator. It is being used as a backup for emergency lighting and fire alarm. Not for manufacturing or processing. 702 does not say anything about the delay in seconds for transfer of power. Is this a fire code or other NFPA requirements for the 10 second rule? This is not for healthcare.
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I feel you are confusing us with your wording. If the generator is being used for manufacturing or processing then it would be 702 optional standby. If all of the emergency lighting that is fed from the same transfer switch and the above, or other optional loads, then the emergency lighting would still need batteries (ditto the fire alarm).

So please clarify, does all of your emergency lighting and fire alarm have batteries that will power the units for the code required time? If not, then your generator is a 700 Emergency generator and the 10 second requirement is valid.
 
My first post missed a word, it should have read "no max". Read the difference between 700.12 and 702.12
 
Strathead said:
I feel you are confusing us with your wording. If the generator is being used for manufacturing or processing then it would be 702 optional standby. If all of the emergency lighting that is fed from the same transfer switch and the above, or other optional loads, then the emergency lighting would still need batteries (ditto the fire alarm).

So please clarify, does all of your emergency lighting and fire alarm have batteries that will power the units for the code required time? If not, then your generator is a 700 Emergency generator and the 10 second requirement is valid.
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My point is that having a 10 sec transfer time is allowable, but not required, for Optional Standby loads.

Which type of inspector is saying 10 secs is required?
What do the job specifications require?
 
jim dungar said:
My point is that having a 10 sec transfer time is allowable, but not required, for Optional Standby loads.

Which type of inspector is saying 10 secs is required?
What do the job specifications require?
Click to expand...
I agree, I was responding to the OP's post where he was responding to you.
 
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