Shunt trip breaker won't reset.

[brittle]

I received a call today from a potential new customer. My understanding is the shunt trip circuit breaker controlling the elevator will not reset. The building maintenance personnel have requested I purchase a new one at a cost of $725.00.

Before we just replace the existing breaker, I’d like to trouble shoot the cause of the shunt trip breaker not resetting. My basic understanding is that if the circuit breaker handle is in the full off position, the cause of the trip may be the shut trip device and but breaker related.

Any suggestions of troubleshooting this situation I would appreciate it.

 

[Energize]

I received a call today from a potential new customer. My understanding is the shunt trip circuit breaker controlling the elevator will not reset. The building maintenance personnel have requested I purchase a new one at a cost of $725.00.

Before we just replace the existing breaker, I?d like to trouble shoot the cause of the shunt trip breaker not resetting. My basic understanding is that if the circuit breaker handle is in the full off position, the cause of the trip may be the shut trip device and but breaker related.

Any suggestions of troubleshooting this situation I would appreciate it.

Where is MDShunk when you need him?:grin: :grin:

 

[jim dungar]

I received a call today from a potential new customer. My understanding is the shunt trip circuit breaker controlling the elevator will not reset. The building maintenance personnel have requested I purchase a new one at a cost of $725.00.

Before we just replace the existing breaker, I?d like to trouble shoot the cause of the shunt trip breaker not resetting. My basic understanding is that if the circuit breaker handle is in the full off position, the cause of the trip may be the shut trip device and but breaker related.

Any suggestions of troubleshooting this situation I would appreciate it.

A source of "control voltage" is required to cause a breaker to "shunt" trip. Remove the control voltage from the breaker's shunt trip leads.
Try to reset the breaker, if it works good, if it doesn't replace it.
If the breaker resets you need to investigate why the control circuit is telling it to trip.

 

[brian john]

disconnect the two #14 AWG's that go into the CB see if there is voltage on these two if not and the CB will not close.

Check the side of the CB and make sure it is a shunt trip not an under voltage release.

Shunt Trip when energized the CB opens, when de-energized CB can be closed.

Under Voltage Release must be energized to close CB, when de-energized CB opens

Remove the front cover of the circuit breaker, remove the shunt trip replace the cover and see if the CB will close, if not the CB is defective.

 

[micromind]

Most breakers I've seen will shunt-trip to the tripped position from either on or off. Since it appears that you can have the breaker in the off position, the shunt-trip coil is likely not energized.

As Jim stated, disconnect the shunt-trip coil (either one of the 2 wires is enough), and turn the breaker on. If it stays on, the problem is not the breaker.

When checking for voltage across the shunt-trip leads, remember that in alot of applications coil power is supplied from the load side of the breaker. Thus, you'll need to test it hot. If you're not comfortable working hot (believe me, no one thinks less of you if you're not), then you'll need to find someone who can work it hot, or kill it and trace wiring until you find the problem. I'd look for an E-stop switch pushed in, or a tripped fire alarm.

 

[wireman71]

But don't run up a $400 dollar bill in labor troubleshooting a $700 dollar device. If you find it's bad they will not be happy to pay you when they just wanted it replaced.

 

[buddhakii]

Had a shunt trip breader that tripped during the fire alarm test but when we went to turn it on it seemed it wouldn't reset. The guy running the job called our boss right away to order a new brkr. As he was talking on the phone I removed the hardware on the front of the breaker and turned it on and it worked fine. Put all the hardware back on the breaker, shut the front door, and turned it on and everything worked fine after that.

 

[brother]

disconnect the two #14 AWG's that go into the CB see if there is voltage on these two if not and the CB will not close.

Check the side of the CB and make sure it is a shunt trip not an under voltage release.

Shunt Trip when energized the CB opens, when de-energized CB can be closed.

Under Voltage Release must be energized to close CB, when de-energized CB opens

Remove the front cover of the circuit breaker, remove the shunt trip replace the cover and see if the CB will close, if not the CB is defective.

I always thought that most shunt trips were 'fail safe' type(normally closed) contacts. Meaning you would turn the power off/or loss of power on the control wiring would cause the breaker to open. In order for the breaker to remain closed then you would have to have power on the control wiring .

Correct me if im wrong please.

 

[brother]

I received a call today from a potential new customer. My understanding is the shunt trip circuit breaker controlling the elevator will not reset. The building maintenance personnel have requested I purchase a new one at a cost of $725.00.

Before we just replace the existing breaker, I?d like to trouble shoot the cause of the shunt trip breaker not resetting. My basic understanding is that if the circuit breaker handle is in the full off position, the cause of the trip may be the shut trip device and but breaker related.

Any suggestions of troubleshooting this situation I would appreciate it.

Check out this site. good info
http://www.teal.com/products/App note AN-16.htm

 

[chris kennedy]

I always thought that most shunt trips were 'fail safe' type(normally closed) contacts. Meaning you would turn the power off/or loss of power on the control wiring would cause the breaker to open. In order for the breaker to remain closed then you would have to have power on the control wiring .

Correct me if im wrong please.

Now I'm confused. I have 8 shunt trips connected to the NO contacts of an Ansul system. 110 to trip.

Elevator breakers the same. Alarm guy supplys me with a relay for elevator shunt. Breaker trips when 110 is applied.

 

[brian john]

A SHUNT TRIP is a coil when energized moves an actuator into the trip device on the circuit breaker resulting in a trip/opening the CB. Unit is de-energized and powered on to trip.

An undervoltage release is energized with the CB closed and upon loss of power to the undervoltage an actuator moves into the trip device on the circuit breaker resulting in a trip/opening the CB. Unit is energized and powered off to trip.

 

[jim dungar]

"Shunt trips" operate when voltage is applied.
"Under voltage trips" operate when voltage is removed

Boy Brian, it looks like timing is everything

 

[ceb]

All I have worked with are just the opposite you apply power to the coil in the shunt to "trip" open the breaker. If you check the coil supply lines and their is power then something like the fire alarm panel has a problem.

 

[brother]

Now I'm confused. I have 8 shunt trips connected to the NO contacts of an Ansul system. 110 to trip.

Elevator breakers the same. Alarm guy supplys me with a relay for elevator shunt. Breaker trips when 110 is applied.

Did anyone go to that website i posted a link to?? It deals with shunt trips and EPO (Emergency Power Off circuits.)

They claim that Fail Safe type circuits are really the best to have.

http://www.teal.com/products/App note AN-16.htm

 

[EBFD6]

I always thought that most shunt trips were 'fail safe' type(normally closed) contacts. Meaning you would turn the power off/or loss of power on the control wiring would cause the breaker to open. In order for the breaker to remain closed then you would have to have power on the control wiring .

Correct me if im wrong please.

If this were the case, everytime the power to the building were interupted the breaker would trip and have to be manually reset. That doesn't sound like it would be too convenient. As others have stated, shunt trips "trip" when power is applied to the coil. They are not a normally open or normally closed set of contacts, it is a trip coil.

 

[brother]

If this were the case, everytime the power to the building were interupted the breaker would trip and have to be manually reset. That doesn't sound like it would be too convenient. As others have stated, shunt trips "trip" when power is applied to the coil. They are not a normally open or normally closed set of contacts, it is a trip coil.

Again i say , did anyone go to the website link i gave?? I understand the principle now about the shunt trips, they do have different types. They have low voltage 'ride through' dc powered shunt trips just for power outages.

check out this site its good info.

http://www.teal.com/products/App note AN-16.htm

 

[EBFD6]

Again i say , did anyone go to the website link i gave?? I understand the principle now about the shunt trips, they do have different types. They have low voltage 'ride through' dc powered shunt trips just for power outages.

check out this site its good info.

http://www.teal.com/products/App note AN-16.htm

I just read the link, and it does talk about having power outage caused nusance tripping as a down side to fail safe wiring. The link is basically all about EPO system wiring which is much different than a shunt trip setup for an elevator. EPO is usually to shut power off to an emergency power fed installation, such as a computer room. I have never seen a fail safe setup for elevator shunt trip. Not saying they aren't out there, just never seen one.

 

[micromind]

One thing about shunt-trips I haven't seen in this thread yet is the fact that most breakers with shunt-trips have a switch inside that opens the coil circuit when the breaker is tripped. This is because the coil will burn up quickly if left energized. If you don't know this, troubleshooting can be a nightmare!

 

[brian john]

Clearing contacts, very common.