Door Hold Opens

[JOHNEO99]

Hi

I am bidding a job where there will be 4 double doors in a corridor with door hold opens (2/per) connected to the smoke detectors to shut them in the event of fire/smoke. My question is can I put 2 hold opens off one relay from a smoke detector or will I need two. I'm not sure if I can name the manufacturer of the fire alarm system and hold opens here but I have that info available. I am meeting with the company in charge of the fire alarm system today and I'm sure this guy can answer my question but I would like to be a bit more informed previous to the meeting.

Thanks

 

[dhalleron]

Most of the time you can install multiple door holders on the same relay. Many of the door holders I deal with only draw about .015 amps at 24 volts or .030 amps at 120 volts.

Double check the relay being used. Most big name brand fire system relays can handle up to .5 amps at 120 volts. I work with at least one combo fire/burg panel that only rates its relays at 28 volts max.

 

[JOHNEO99]

Thanks Dale

I have only seen these relays in the field and never wired one complete. I only took a whip thru the door frame and others terminated the rest. How many wires come off the relays? This is a IR LCN 4040SE holder and the FACP is Siemens MXL.

The holder is 24VAC-DC Nominal 10%-15% @ .090 Amp. Max and 120VAC-DC Nominal 10%-15% @ .030 Amp. Max.


Be nice to get a hold of the fire alarm guy and get one of these relays.

Thanks again

 

[dhalleron]

If the relay is addressable it would have 2 wires for the SLC or data loop and it will have 2 normally closed terminals to make and break one side of the power to your door holder.

Just picture the door holder as a light bulb and the relay as single pole switch except the switch has an extra pair of wires that controls it.

 

[goldstar]

Is there a magnetic door holder (MDH) circuit ? If so you should be tying into that. It seems strange that a mere smoke detector should determine whether a given door should be shut or not. I thought the main idea during a fire was to "compartmentize" a smoke condition so it doesn't spread. It just seems weird to me that door "A" would shut and not door "B".

 

[JOHNEO99]

The plan says to tie all door holders into the smokes. So yes all the holders will close at the same time according to plan. Im not too familiar with fire alarm and wasnt sure how many doors i could control with one relay. I guess theres more than one way to skin the cat. I will meet with siemens tommorrow to get the low down since we are buying the devices and relays from them. Really curious as how the should be laid out, piped and wired. I really didnt want to have a relay in the FACP but i think I may have to.

 

[goldstar]

From my experience, just because an engineer shows it on the drawings doesn't mean the drawings are 100% correct. Engineers generally cover their tails by showing things on the drawings - you're supposed to know (or get the expertise to know) exactly how to tie them in. The smoke detector circuit is not going to provide the power for the MDH. The MDH power circuit is going to originate from the FACP or an auxilary panel anyway, why not just break the circuit there via a relay ? That way all doors close at tha same time.

 

[dhalleron]

Depending on the sequence of operations all doors might not close at the same time, but sounds like they will on your project. There is a whole section in NFPA 72 about door holder release. The purpose is to prevent smoke travel from one area to another. The doors don?t need to close on a general alarm in all cases.

Sometimes the door holders are powered locally by 120V and the relay is in the smoke detector base. In those cases usually only the smoke detectors near the doors will release the doors. Even when powered by 24V the doors might only need to close on local smoke detection.

 

[JOHNEO99]

I will do whatever it takes to get it done right and if I cant do it then I will just pipe the openings and whip the door holders like I have in the past. I figure since i don't have a full time job right now I would try to figure out this fire alarm stuff and bid everything not just the piping. I have the time to learn. I had a friend of mine who has done some fire alarm come to the job and explain how the holders worked (not that I fully understood the mechanics but I got a good picture) and when he did this I thought he was saying the relay would be remote but after reading up on the topic I suppose we will need a relay module in the panel or use the existing one. I thought there may be a relay I could use down the line and use a separate power source for it. I will post what I see today as far as the MDH circuit is concerned.

The fire panel is MXL which I think is addressable but the wiring in the basement (40 years old) is solid #14 thhn 4 wires which I believed to be a zone. I'm really just trying to learn and understand the system better and if I feel comfortable I will wire up the 5 new smokes and tie the 4 door holders and damper to the system. If I do the wiring it will obv be programmed and terminated at the panel by an alarm company. All the NAC devices are already in place down there so it would just be the 5 new smokes and tie the oor holders and one new damper into the system.

I appreciate the input.

John

 

[goldstar]

There are two basic types of addressable FA systems. The first has a control unit that you can buy over the counter at your local alarm supply and program yourself. In this case the facility that it is installed in basically owns both the FA system AND the program. The second type (usually installed in larger facilities) is considered a proprietary system in which case the alarm company servicing the FA system owns the program but the facility owns the FA system (basically the hardware). These alarm companies will not allow anyone, other than their own company reps, to open the program and make any changes unless someone from the facility where it's installed signs a "hold harmless" document absolving the alarm company from any and all faults in the system from that point on. Obviously, no one wants to do that.

Anyway, the reason I'm telling you this is because if it is a proprietary system that you're dealing with then the alarm company servicing this system should be the ones telling you how to make your connections and it should be done under their supervision. Be careful with this. The liability could be greater than what the job is worth. I'm not trying to scare you out of doing the work, just make sure you have all bases covered.

 

[JOHNEO99]

It is a proprieitory system and I am meeting with the fire alarm company to go over their requirement when they get a hold of me which doesnt seem to be much of a priority to them.

If I do the install and the alarm company terminates at the panel and re-programs the system how does the liability fall on me?

John

 

[gadfly56]

The Joy of Siemens

The Joy of Siemens

Ahhhh, yes, the MXL.

First, the reason that the spec or design calls for the doors to close is that waaaaay back at the beginning of time, somebody wrote the spec/design in the age of conventional panels. During that era, fire or smoke control doors were activated by smoke detectors located within about 3' of either side of the door and equipped with RELAY BASES. When the detector was activated it tripped the relay in its base, allowing the current to be dropped to the mag lock and presto! the door closes. Note that ONLY the detectors which are activated will also activate their relay bases. If you need all the doors to close on any alarm, this won't work for you.

Now we live in an enlightened age, with addressable panels but alas, also with lazy design firms who figure if the spec was good enough for grandad, it's good enough today.

You can still get relay bases for the MXL. The model number is DB11-XRS. The default program setting is that when the smoke detector in the base is activated, the relay in the base is as well. Alternatively, you can use the TRI-R relay module. You can map either the two smoke detectors on either side of the door (now installed in the standard DB-11 base) to the relay, use a system flag "Any Alarm", or map additional detectors or other addressable devices to the relay. Two relay bases are cheaper than one TRI-R, but you can program all the TRI-R's to go on "Any Alarm".

The TRI-R has only ONE relay output. It also has one addressable monitor input.

The TRI-R is rated for 4 amps resistive in 120VAC or 30VDC, or between 2 and 3.5 amps if the power factor is between 0.35 and 0.6.

My company is happy to sell you as many as you like, but you'll need a Siemens distributor to program the panel for you.

 

[goldstar]

If I do the install and the alarm company terminates at the panel and re-programs the system how does the liability fall on me?

John

In all fairness it really doesn't. In all probability it will never come to this, but if there is ever a fire incident, lawyers use the shotgun approach as opposed to the rifle approach to suing people. Anyone involved with the project is named in the suit. In your case, just go with your plan, install the devices in accordance with the FA company's recommendations, have them make the final connections, re-program the software and sign off on the job. At that point, unless you (or your helper) did something weird or horribly wrong (like ran open wiring through an air duct) that might not show up for several months, you're in the clear.