Emergency Disconnect Location

P

Power Solutions

Member
Hi All,
We were recently asked to complete a project that was started by another firm. Those are always fun.
Single phase 120/240 V from the utility.
Three phase 230 V from a digital converter to at 10hp propane pump motor.
Question one. Is there a code requirement for the emergency shut off relay to be before or after the converter?
The converter is only used for this one pump.
Both options are in the same non-hazardous location.
I believe either location is ok. Thoughts?

Second question. 514.11 states an emergency shut off need to be between 20 and 100 ft away for the dispenser. The intent seems to be able to allow a person to shut the system down if there is an issue without being in the class 1 division 2 zone. Can a second emergency shut off be installed in the class 1 Division 2 zone?

Dj
 
Code wants an emergency shut off between 20 and 100 ft away. Does not prohibit additional shut offs. Last tank/dispenser had 2, one at the required distance, and one closer in. All devices met the installation requirements.
 
Power Solutions said:
Second question. 514.11 states an emergency shut off need to be between 20 and 100 ft away for the dispenser.
Click to expand...
Is this a motor fuel dispensing location? If not 514 likely does not apply. If you are only filling portable containers I don't know it would be considered motor fuel dispensing unless you actually are connecting to a container that is fixed to a vehicle?
 
kwired said:
Is this a motor fuel dispensing location? If not 514 likely does not apply. If you are only filling portable containers I don't know it would be considered motor fuel dispensing unless you actually are connecting to a container that is fixed to a vehicle?
Click to expand...
It may. See 515.10.
 
It’s essential to read Article 514’s Scope (Section 514.1). The key is dispensing of motor fuel. Also consider the IN. Another Technical Committee (NFPA 30A) actually controls Article 514, not CMP 14.

Getting back to the OP:

Q1: Interpret the last sentence of Section 514.11 as you will:
The emergency shutoff device shall disconnect simultaneously from the source of supply, all conductors of the circuits, including the grounded conductor, if any. Equipment grounding conductors shall remain connected.
Click to expand...

The emphasis is disconnecting the conductors.


Q2: An emergency disconnect must meet all the requirements of Section 514.11(A). That is, it must be not less than 20’ from the fuel dispensing device. The practical reason is to get it out of and not above (514.7) Classified location.

That said, auxiliary disconnects would be permitted for maintenance, not emergency, purposes. (I could probably guarantee no one would attempt to use the disconnect in an emergency situation.)
 
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