Fire Alarm disaster??

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jahilliard

Senior Member
So we were drilling through a solid block wall when we hit a conduit and shorted the wires. The elevators shut down and the FA panel went to flashing on all zones. It's an older simplex panel and all the expansion cards were flashing even the ones resistored out BUT there was never any audible alarms and one elevator just stopped in place. Turns out there is a 120V circuit that we have yet to identify running through the conduit along with the 24V FA circuits. This 120V has something to do with the elevators obviously but not sure exactly why or if it has anything to do with the FACP. We have completely shut down the FA panel due to the fact it will have to be repaired because of the surge. The bigger question is...if the 120V has nothing to do with FACP as far as we know, is it allowed in the conduit with the 24V zone wires or is the original installation incorrect. Something doesn't seem right and we are still searching but this should have been a fairly easy repair and it has turned into a fairly giant one. Also, we replaced a few fuses and the elevators are fine once we bypassed the FACP.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
So we were drilling through a solid block wall when we hit a conduit and shorted the wires. The elevators shut down and the FA panel went to flashing on all zones. It's an older simplex panel and all the expansion cards were flashing even the ones resistored out BUT there was never any audible alarms and one elevator just stopped in place. Turns out there is a 120V circuit that we have yet to identify running through the conduit along with the 24V FA circuits. This 120V has something to do with the elevators obviously but not sure exactly why or if it has anything to do with the FACP. We have completely shut down the FA panel due to the fact it will have to be repaired because of the surge. The bigger question is...if the 120V has nothing to do with FACP as far as we know, is it allowed in the conduit with the 24V zone wires or is the original installation incorrect. Something doesn't seem right and we are still searching but this should have been a fairly easy repair and it has turned into a fairly giant one. Also, we replaced a few fuses and the elevators are fine once we bypassed the FACP.

The 120 may have been for the elevator shunt trip, especially if the elevator shut down was simply a halt wherever it was and not a return to the primary or seconday landing.

I hope your insurance premiums were all paid up! If the short caused 120VAC to find its way onto the 24VDC circuits, the panel is likely complete toast. If they have Simplex repair it, it's going to be very expensive.
 

jahilliard

Senior Member
The 120 may have been for the elevator shunt trip, especially if the elevator shut down was simply a halt wherever it was and not a return to the primary or seconday landing.

I hope your insurance premiums were all paid up! If the short caused 120VAC to find its way onto the 24VDC circuits, the panel is likely complete toast. If they have Simplex repair it, it's going to be very expensive.

Yea no kidding. Cintas services the system and honestly I'm looking to see if there's anything that can divert the liability to others due to the 120V wire not even being part of the system. The system is a mess and hasn't been tested since 12/13. Yep two minutes of drilling turns into thousands in repairs.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
If the 120 volt wire is control rather than power, then there may not be a violation there, especially if the circuit can be identified as Class 2 or Class 3.
Even a limited power 120 volt circuit can wreak havoc with low voltage DC circuitry.
But if there is no power limitation or if the elevator control is not considered "functionally related" to the alarm circuitry, always varying from inspector to inspector, you could still have an argument.
<sigh>.

Tapatalk!
 

nhfire77

Senior Member
Location
NH
we replaced a few fuses and the elevators are fine once we bypassed the FACP.

"Bypassed" the FACP how?

What fuses did you replace?


I doubt an existing NEC violation will shift responsibility from you, but I feel your pain and understand what you are looking for. I hope you don't get caught answering leading questions from their insurance company like:

Did the existence of this improperly wired and dangerous fire alarm raceway, that had yet to cause any damage, lead you to drill in to the conduit?
If it was wired properly, would you have hit it anyway?
 

jahilliard

Senior Member
"Bypassed" the FACP how?

What fuses did you replace?


I doubt an existing NEC violation will shift responsibility from you, but I feel your pain and understand what you are looking for. I hope you don't get caught answering leading questions from their insurance company like:

Did the existence of this improperly wired and dangerous fire alarm raceway, that had yet to cause any damage, lead you to drill in to the conduit?
If it was wired properly, would you have hit it anyway?

We used the elevator key to bypass the fire alarm to allow the elevators to operate regardless of the status of the FACP. Ultimately we accept responsibility for what we did BUT if there is 120V AC present where there shouldn't that would obviously contribute, if not totally create, the damage to the 24V DC panel. In other words, had the installation been installed properly, some fuses may have blown but no surge would've occured. That's all we are saying.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
We used the elevator key to bypass the fire alarm to allow the elevators to operate regardless of the status of the FACP. Ultimately we accept responsibility for what we did BUT if there is 120V AC present where there shouldn't that would obviously contribute, if not totally create, the damage to the 24V DC panel. In other words, had the installation been installed properly, some fuses may have blown but no surge would've occured. That's all we are saying.

That's a mighty slim peg to hang your hat on. If I were you, and this advice is worth every penny you're paying for it, I'd let my insurance company and/or lawyer do the talking to the client from now on. At least as far as the incident is concerned.

With the elevator now operating in "Fire" mode, is the building now on fire watch? Depending on the size of the building, that can get real expensive, real fast.
 

__dan

Senior Member
I don't see where you are immediately liable and also, that's a determination made by your insurer, what they will pay, and not a finding made by you for your insurer. For example, if you said "I will pay for the damages" or made a partial payment indicating acceptance of the claim, your insurer would freak out for accepting liability that they may have to now pay for.

There is a legal doctrine, I forget the name, but if you encounter a situation that you cannot reasonably foresee, you may not be liable. For example, drilling blindly into concrete block, how can you reasonably foresee there is a conduit in your drilling path. I would think if you claim the conduit was hidden from your view and was not seen or known of in advance, you may not be liable and the opposing attorney may have to show where you were deficient or negligent in your methods (you should have x rayed, magnetic detected, hired a clairvoyant ...). It's their argument to make, what was your duty to detect and foresee the conduit that was hidden from you.

If the situation is one that is easily or reasonably foreseen, then yes you may be liable.

The property owner is the one responsible for providing the conditions and environment under which its employees and contractors work. It could easily be an accident that goes on the owner's property insurance. If there is big money or personal injury, loss of life, you would need to know this.

Whatever you do, do not accept liability in any way and immediately notify your insurer. Let them decide what they want to do with a potential claim. Speak to your insurance agent and he will tell you this.
 

jahilliard

Senior Member
I don't see where you are immediately liable and also, that's a determination made by your insurer, what they will pay, and not a finding made by you for your insurer. For example, if you said "I will pay for the damages" or made a partial payment indicating acceptance of the claim, your insurer would freak out for accepting liability that they may have to now pay for.

There is a legal doctrine, I forget the name, but if you encounter a situation that you cannot reasonably foresee, you may not be liable. For example, drilling blindly into concrete block, how can you reasonably foresee there is a conduit in your drilling path. I would think if you claim the conduit was hidden from your view and was not seen or known of in advance, you may not be liable and the opposing attorney may have to show where you were deficient or negligent in your methods (you should have x rayed, magnetic detected, hired a clairvoyant ...). It's their argument to make, what was your duty to detect and foresee the conduit that was hidden from you.

If the situation is one that is easily or reasonably foreseen, then yes you may be liable.

The property owner is the one responsible for providing the conditions and environment under which its employees and contractors work. It could easily be an accident that goes on the owner's property insurance. If there is big money or personal injury, loss of life, you would need to know this.

Whatever you do, do not accept liability in any way and immediately notify your insurer. Let them decide what they want to do with a potential claim. Speak to your insurance agent and he will tell you this.

Yea that's exactly what we have done. I have left it up to the adjuster to do what they feel is best. We haven't admitted to anything. Good experience I guess. Thanks for all the feedback.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
In cases like this are we supposed to X-ray before you drill?

I know if this was a tension slab we would have to.
 

nhfire77

Senior Member
Location
NH
We used the elevator key to bypass the fire alarm to allow the elevators to operate regardless of the status of the FACP. Ultimately we accept responsibility for what we did BUT if there is 120V AC present where there shouldn't that would obviously contribute, if not totally create, the damage to the 24V DC panel. In other words, had the installation been installed properly, some fuses may have blown but no surge would've occured. That's all we are saying.

Dont let the elevator folks know about that, it might be a huge deal using those keys in that manner, depending on what state you are in. Most elevator guys I've dealt with are patient but would come unglued if they knew that was happening on a car they worked on recently. just saying...
 

jahilliard

Senior Member
Dont let the elevator folks know about that, it might be a huge deal using those keys in that manner, depending on what state you are in. Most elevator guys I've dealt with are patient but would come unglued if they knew that was happening on a car they worked on recently. just saying...

The Taylor Elevator guy was standing right there. Any way... I would really like to know the real answer to the question "can we mix voltages?". For example...Today I was talking to the Fire Alarm Company that we are doing a Multi-family project with. Well, the conduit we installed for them goes under a large drive way...and now there are some change orders where we need to get from one bldg to the other. So I suggested the FA company install 600V rated THHN wire so that we can use the conduit instead of having to directional bore under the drive way etc. His response was..you can't mix voltages...My respone was, yes you can as long as the insulation ratings are equal...his response was, I'll fail the inspection...Why?...because the inspector said you can't mix voltages...My response was can you please have the inspector you're talking about contact me so that I can educate myself as well as my installers the real reason why. Haven't heard a thing since! What's the real answer here? I genuinely would like to know. As far as I have gathered so far...EVERYONE in this field assumes you just can't do it. the NEC says you can....so why do sop many believe that you can't?? Help me!:?
 

jahilliard

Senior Member
Ok, maybe it was obvious to everyone else, but no one was willing to show me where the explanation of the rule was...none the less I have found the information explaining that it is not allowable to mix Class 2 and 3 with Class 1 as well as electric light, power, NPLFA etc. without meeting certain requirements etc. and being functionally related. Thanks
 

Fulthrotl

~Autocorrect is My Worst Enema.~
So we were drilling through a solid block wall when we hit a conduit and shorted the wires. The elevators shut down and the FA panel went to flashing on all zones. It's an older simplex panel and all the expansion cards were flashing even the ones resistored out BUT there was never any audible alarms and one elevator just stopped in place. Turns out there is a 120V circuit that we have yet to identify running through the conduit along with the 24V FA circuits. This 120V has something to do with the elevators obviously but not sure exactly why or if it has anything to do with the FACP. We have completely shut down the FA panel due to the fact it will have to be repaired because of the surge. The bigger question is...if the 120V has nothing to do with FACP as far as we know, is it allowed in the conduit with the 24V zone wires or is the original installation incorrect. Something doesn't seem right and we are still searching but this should have been a fairly easy repair and it has turned into a fairly giant one. Also, we replaced a few fuses and the elevators are fine once we bypassed the FACP.

first thing that popped into my head was shunt trip for the feed
for the elevator.

so what you are saying is that when you drilled into the conduit,
you shorted the wires together, putting 120 vac onto 24 vdc
terminals?

doesn't change anything but i find it very odd that the control
riser for the elevator would be encased in a block wall. every
one i've ever seen is surface ran inside the elevator shaft, with
piping to control stations, etc.

even where the elevator shaft is block instead of double drywall,
i've never seen it piped in the wall....

i don't see an exit strategy for getting out of this one, to be honest.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
first thing that popped into my head was shunt trip for the feed
for the elevator.

so what you are saying is that when you drilled into the conduit,
you shorted the wires together, putting 120 vac onto 24 vdc
terminals?

doesn't change anything but i find it very odd that the control
riser for the elevator would be encased in a block wall
. every
one i've ever seen is surface ran inside the elevator shaft, with
piping to control stations, etc.

even where the elevator shaft is block instead of double drywall,
i've never seen it piped in the wall....

i don't see an exit strategy for getting out of this one, to be honest.

Note that there were fire alarm cables in the conduit. If you surface mount the conduit on the interior wall of the elevator hoistway, everything in that conduit has to be only for the elevator. You can't use the hoistway as a chase for other wiring to go from floor to floor.
 
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