Elevator Air Cond. Circuit
- Thread starter nvcape
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Re: Elevator Air Cond. Circuit
Nvcape, I have wired alot of elevators in (4) states and have never seen a design calling for a circuit that wasn't needed.
The elevators I have wired with heat were served with the required source, even had one with a 208 1ph unit heater, they were all 20 amp circuits.
Roger
Nvcape, I have wired alot of elevators in (4) states and have never seen a design calling for a circuit that wasn't needed.
The elevators I have wired with heat were served with the required source, even had one with a 208 1ph unit heater, they were all 20 amp circuits.
Roger
Re: Elevator Air Cond. Circuit
Roger, thanks for the reply. The 99 code is not that old here, so can use some help. NFPA 3-9.4 requires that a heat detector shuts off elevator power before sprinkler operation. Elsewhere(3-9.3), it tells you to use a smoke also in the shaft and equipment room to lower the car first; but no where that I know of does it tell you to have controls to make sure the car is lowered before you kill power. We also are required to add an auxillary contact to kill the battery power too. How do other areas handle this. Next, are they requiring you to kill the cab lights and air conditioning too?
Roger, thanks for the reply. The 99 code is not that old here, so can use some help. NFPA 3-9.4 requires that a heat detector shuts off elevator power before sprinkler operation. Elsewhere(3-9.3), it tells you to use a smoke also in the shaft and equipment room to lower the car first; but no where that I know of does it tell you to have controls to make sure the car is lowered before you kill power. We also are required to add an auxillary contact to kill the battery power too. How do other areas handle this. Next, are they requiring you to kill the cab lights and air conditioning too?
ron
Senior Member
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- New York, 40.7514,-73.9925
Re: Elevator Air Cond. Circuit
There is no national requirement to ensure that the car is at a floor prior to elevator power shunt trip.
Consider that the smoke detector at the top of the shaft will begin recall well in advance of the temperature reaching 135 (heat detector) or 165 degrees (sprinkler head).
There is no national requirement to ensure that the car is at a floor prior to elevator power shunt trip.
Consider that the smoke detector at the top of the shaft will begin recall well in advance of the temperature reaching 135 (heat detector) or 165 degrees (sprinkler head).
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- Lockport, IL
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- Semi-Retired Electrical Engineer
Re: Elevator Air Cond. Circuit
My read on this is as follows: IF an A/C unit is installed, THEN it must be served by a dedicated branch circuit. I may be splitting a very fine hair here, but I believe the key to understanding 620-22(B) (1999 version) is to focus on the first sentence, and in particular upon the single occurrence of the word ?the.? The exact wording of this sentence is, ?A dedicated branch circuit shall supply THE (my emphasis) air-conditioning and heating units on each elevator car.? This does not require that an A/C unit be installed, nor that a dedicated branch circuit be provided, just in case the owner decides to install an A/C unit sometime in the future. If there is no A/C unit, then you don?t need to install a dedicated branch circuit for an A/C unit.
Good luck on this one. The Inspector might read the article differently, and can easily call it the other way.
My read on this is as follows: IF an A/C unit is installed, THEN it must be served by a dedicated branch circuit. I may be splitting a very fine hair here, but I believe the key to understanding 620-22(B) (1999 version) is to focus on the first sentence, and in particular upon the single occurrence of the word ?the.? The exact wording of this sentence is, ?A dedicated branch circuit shall supply THE (my emphasis) air-conditioning and heating units on each elevator car.? This does not require that an A/C unit be installed, nor that a dedicated branch circuit be provided, just in case the owner decides to install an A/C unit sometime in the future. If there is no A/C unit, then you don?t need to install a dedicated branch circuit for an A/C unit.
Good luck on this one. The Inspector might read the article differently, and can easily call it the other way.
Re: Elevator Air Cond. Circuit
Learned a little more. The NFPA 2002, A6.15.4.4 states that elevator power shutdown is to have a delay so that the cab can be returned. While the elevator controller responds to the smoke sensor signal, and the door is opened, I don't think they have an auxiliary contact to tell me this. As the timing would change with the building height, elevator speed, and if primary or secondary floor, timing does not make sense. Has anyone figured this out?
Learned a little more. The NFPA 2002, A6.15.4.4 states that elevator power shutdown is to have a delay so that the cab can be returned. While the elevator controller responds to the smoke sensor signal, and the door is opened, I don't think they have an auxiliary contact to tell me this. As the timing would change with the building height, elevator speed, and if primary or secondary floor, timing does not make sense. Has anyone figured this out?
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