Shunt Trip Breakers in IT rooms

Status
Not open for further replies.
T

twayne

Member
Would you folks happen to know whether or not it is a code requirement to have a shunt trip breaker tested after it is installed, The application of this 150A 480V 3 phase breaker is for a computer room air conditioner. The computer room has been in existance for many years but due to additional equipment of course the heat load went up and therefore need for more air. The new shut trip breaker will be connected to existing fire alarm panel along with all the other equipment in this IT room. Question is again, is there a NEC requirement or any other codes that demand this new breaker be subject to a full functional tested after installation.

Appreciate your assistance,
Wayne
 
The new shut trip breaker will be connected to existing fire alarm panel along with all the other equipment in this IT room. Question is again, is there a NEC requirement or any other codes that demand this new breaker be subject to a full functional tested after installation
Click to expand...

In my opinion (IMO) why would you not want to test it?.Isn't this a critical circuit? and wouldn't you want it to work properly when the situation happends?
Too many installations have been designed/installed incorrectly. I always suggest that you call the fire alarm company and ask what the output module is capable of delivering in the shunt trip signal and then call the breaker manufacturer and ask what current is required to actually activate that shunt trip mechanism, you maybe surprised to find out that the fire alarm signal can not deliver enough current to trip the breaker.

However to answer your question. "Only if the AHJ requires it", which he should.
Just my $.02
 
Shunt Trips in IT rooms

Shunt Trips in IT rooms

David,
I appreciate your prompt responce, i'ts not that I don't want the breaker tested even though it is new. As always here (like eveywhere) time is critical factor, we are haveing an outage this Saturday to replace a ATS an install a larger panel which will service this IT room, this is a 24/7 operation and it is extremely difficult to schedule an outage with this organization. That's the reason for my question about the codes, we have such a narrow window to accomplish this task and we may not have the time to test the shunt during (after the IT equipment is shut down or before it is brought back on line could possibly give us enough time but it's doubful) we will have to schedule another outage to test the shunt. Supposedly the shut requirements (voltage) and the fire alarm panel feeding the shunt are matched (verified by electrician). What do you think about testing the breaker after being installed in it's can (even before the line and load is connected) by simply applying the proper voltage and then, when go to the terminal and (of course after checking the voltage from the fire alarm panel) make the final connection.

Thank,
Wayne
 
we are haveing an outage this Saturday to replace a ATS
Click to expand...
Then can you activate the shunt trip to shut down the power.
Supposedly the shut requirements (voltage) and the fire alarm panel feeding the shunt are matched (verified by electrician
Click to expand...
It's not the voltage I am concerned about, it's the amount of current necessary to activate the shunt trip mechanism.
What do you think about testing the breaker after being installed in it's can (even before the line and load is connected) by simply applying the proper voltage and then, when go to the terminal and (of course after checking the voltage from the fire alarm panel) make the final connection.
Click to expand...
That also would be fine.
 
Is the fire alarm system a 'pre-action system'?

Also usually it is much easier to shut down HVAC equipment via the 24 VAC control circuit.
 
A job I recently inspected had several shunt trip breakers installed. They tested all of the breakers (I think there were 10) and one of the breakers would not close after it opened. They replaced it. I did not require the testing, they wanted to test them.

You should have seen them trying to close that breaker...talk about frustration.
 
The answer to your original question is that there is no code requirement to test the shunt tripping systems from 645.10.
Many data centers cannot withstand an HVAC outage for long period of time due to heat rate of rise issues and prefer not to test the EPO in hopes that it will never work (which is a mistake in my opinion).
 
If you have an outage planned anyway, it may be an opportunity to pull the shunt trip conductors off and install a small lamp that would simulate the current needed for the shunt trip mechanism, after an EPO is activated. check the light. This way at least you know there is voltage and the ability to transfer some current.
 
Shunt Trip breaker in IT Rooms

Shunt Trip breaker in IT Rooms

At the initital install ... yes. It sounds like from the OP this is an existing installation, where the activation of a shunt trip will activate all.

Ron,

You are absolutely correct in your assumption. We have since the last post completed the project and during the outage tested the shunt before the line or load was connected, all worked well.

iwire,
This is a pre-action system.

Bye the way, I said all worked well, not exactly, after the work was completed and the old 2000A main was reset the load was gradually brought up. After about 200A the main tripped and continued to do so during several attempts. Now getting very late (into Sunday morning) with no other options, called another Elect. Contr. which fabed some buss, parallel 3"x1/2" x 24", removed the breaker and insstalled the solid buss, needless to say the facility was up and running before all the folks came back to work Monday morning. Realize this is just a temp fix, recondition breaker on the way. Always when you're very tired and least expect something to go wrong.
 
iwire said:
Also usually it is much easier to shut down HVAC equipment via the 24 VAC control circuit.
Click to expand...

not always compliant with all the codes though (fire marshall). I don't know what codes are violated, but I've had FM's require unit power to be shut down directly since unit boards will still have fan run for cool down sequence etc after controls call for shutdown.
 
Status
Not open for further replies.
Top