Tandem Breakers in Hospital

Status
Not open for further replies.
J

jamism

Member
Hello Everyone

I am currently working on a hospital project where part of floor was being fed with from a panel in which all the breakers where tandem breakers. I wanted to see if anyone knew if this was a legal installation in a health care facility. I looked through the 96 NEC and I could not find anything. Thanks everyone.
 
How many single overcurrent protection devices does this add up to in the panel(s)? If there are more than 42 OCPDs in a panel, this is a violation of NEC 408.15 and is not allowed.
 
NOT recommended, specially in a hospital. Tandem breakers shall not exist at all (personal opinion) They just add a safety hazard.

For example, if originally each panel consisted of 42 spaces, now you have 84 branch circuits (assuming all breaker spaces are used by a tamdum breaker) I agree with earshavewalls Tandem breakers are a NO, NO and NO!! :mad:
 
Last edited:
l3city said:
NOT recommended, specially in a hospital. Tandem breakers shall not exist at all (personal opinion) They just add a safety hazard.

For example, if originally each panel consisted of 42 spaces, now you have 84 branch circuits (assuming all breaker spaces are used by a tamdum breaker) I agree with earshavewalls Tandem breakers are a NO, NO and NO!! :mad:
Click to expand...

A UL listed device manufactured by a company to be installed in a panel specifically designed to accept such device is a no no?...........
 
l3city said:
I agree with earshavewalls Tandem breakers are a NO, NO and NO!! :mad:
Click to expand...

That is a personal opinion, as long as the panel manufacturers circuit limit is not exceeded it is a NEC compliant installation.

For example 40/20 panel would need 20 tandems to reach the 40 circuit limit.
 
cant go over

cant go over

iwire said:
That is a personal opinion, as long as the panel manufacturers circuit limit is not exceeded it is a NEC compliant installation.

For example 40/20 panel would need 20 tandems to reach the 40 circuit limit.
Click to expand...

Most panels have a section near the bottom that are designed so the tantem breakers wont go in, and it is right amount of spaces so the box cant go 42 breakers if you install tandems on all the others
 
hey guys don't panic!! read my statement specially the two words in parenthesis :smile: :

l3city said:
NOT recommended, specially in a hospital. Tandem breakers shall not exist at all (personal opinion) They just add a safety hazard.
Click to expand...
:smile:
 
earshavewalls said:
I didn't say that tandem breakers were not allowed, I only said that you cannot exceed 42 OCPDs in a panel.
Click to expand...

What's the reason behind this rule anyway? How did they arrive at 42. Why not limit to 40, or bump it up to 44? The rule couldn't have been safety based, could it have?
 
Still not clear

Still not clear

Hello everyone thanks for responding. I understand how everyone feels about tandem breakers, but those anyone know specifically where in the NEC this is a "no no" for health care facility? Or where they are even mentioned in the NEC, I would love to read the section.
 
jamism said:
but those anyone know specifically where in the NEC this is a "no no" for health care facility? Or where they are even mentioned in the NEC, I would love to read the section.
Click to expand...

No, the NEC does not mention tandems.

To the NEC and UL tandems are no different than any other breakers.

They can be used and installed per manufacturers instructions.

I don't care for them either but that is a design issue not a code issue.
 
The restriction on the number of overcurrent devices allowed within panelboards started waaaayyyyy back when all wire insulation was rubber. This condition produced a lot of heat within panelboards and was supposedly the cause of a huge hotel fire in Chicago back in the 20's or 30's.
The NEC is looking at proposals right now to eliminate this requirement. This change is being backed or pushed by Eaton/Cutler Hammer. The Canadian Electrical code does not carry this restriction.
I don't write the codes, I'm just the messenger.
The code does not even mention tandem breakers, so they are not prohibited from being used as long as they are used in compliance with all other codes for overcurrent devices and panelboards.
 
earshavewalls said:
The restriction on the number of overcurrent devices allowed within panelboards started waaaayyyyy back when
Click to expand...

Yes there is currently an NEC limitation of 42 overcurrent devices in a lighting and appliance branch circuit panel.

However you will never exceed that limitation using tandem breakers as long as the manufacturers directions are followed.

Even if the NEC removes the 42 OCD limitation we will still have to use the breakers and the panels per their listing.
 
Heck, the wiring space in most panels is so tight you'd be hard-pressed to use the panel's listed maximum without it being a major pain. :rolleyes:

Maxed-out panels are the rule in the cinema biz....and hack work abounds. Mainly from "projectionists" who fancy themselves sparkys as well.

I'd love to get pics, but the current anti-piracy rules won't allow even a service tech to have a camera in a booth.. like I'm gonna pirate a movie one frame at a time...:rolleyes:

OT trivia for ya: Film is projected at 24 frames per sec., so a two-hour movie has 172,800 frames. (24fps x 60sec/min. x 120min. = 172,800)

But a technical trick is in the mix: each frame is flashed onscreen 2 times (to reduce visible flicker) in cinemas (3 times per frame in small screening rooms).

That's a lotta frames!!
 
First of all hospitals should be using bolt in style breakers, I haven't seen a tandem breaker on this type of panel, therfor the 42 circuit would not be a problem.
 
Mooseamp said:
First of all hospitals should be using bolt in style breakers,
Click to expand...

Moose there is no requirement that bolt on breakers have to be used in any occupancy.

I agree you would expect bolt-ons in a hospital.
 
Actually most Isolation Panels use snap-in breakers.

Roger
 
That panel is going away

That panel is going away

thanks for everyones help in this question. After reading how everyone feels about this issue, I am going to request that this panel be reconfigured to single, non tandem, breakers.
 
Status
Not open for further replies.
Top