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How is the circuit classified

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czarstoo

Member
I have a client with a transfer switch installed outside of his garage for use with his emergency genset. He wants to install a set of meters in his garage to allow him to monitor the output of his genset. Reliance makes a nice little meter assembly which utilizes current transformers. However, the assembly requires that the genset supply wires be through the meter enclosure which is not consistent with mounting the meter assembly in the garage. I would like to install the current transformers in the transfer switch enclosure and install the meter enclosure in the garage. The current transformer is 1000:1 so the transformer secondary current is in the 0 - 50 mA range and the voltage across the load resistor in the meter is in the 0-5 VAC range. The current sense secondary wires are not control wires, but I'm thinking that they might be considered to be signaling.

The question is this: How would the circuit between the current transformer secondary and the remote meter be classified with respect to NEC article 725??
 
ryan_618

ryan_618

Senior Member
Location
Salt Lake City, Utah
Re: How is the circuit classified

Well, if it is 5 volts and 50 miliamps, it would be .25VA. That would put you in the class 2 range. The question then becomes, is your power source of a type listed in 725.41(A)?
 
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czarstoo

Member
Re: How is the circuit classified

The power source is a 1000:1 current transformer that is manufactured for Reliance to use in their Wattmeter boxes. It is not listed for serarate purchase.

Does that mean the the circuit is not a class2??

However, the Wattmeter boxes and Transfer Switches that utilize the current transformers are UL listed as completed assemblies. I want to mount the current transformers in the transfer switch to sence the generator current and display it on the meters located 50 feet away
 
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czarstoo

Member
Re: How is the circuit classified

The current transformer is not listed as anything. Is is part of a UL listed Wattmeter Assembly.
 
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