DC Problem with door holders

Status
Not open for further replies.
F

Fordean

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
Installing Door holders. Ran 14/2 firealarm cable to door holders for release. Run is about 225 feet at its longest holder. (Holder # 4) ( and includes 1,2,3 holders closer).

Door holder wont hold. Rated @ 24Vdc. @.015 amps.

Have 27.00 Vdc readings but still wont hold.


Holders are T tapped along the way. Would series wiring matter on DC.? Available at board in Fire alarm ( Simplex) Aux contact 2 amp Resistive. Not sure what is actually available on Simplex end here.
 
Assuming you have self-closing doors with magnetic holdback, check the tension screw on the self-closer.

FL Bldg Code says 3 second minimum for a self closer to move the door from 70 degrees to within 3 inches of the strike (to keep from chopping off hands). Open the door to 70 degrees and let it go; count 1 mississippi, 2 mississippi, etc. and see how your setting is. If it slams too quick, ease off on the setting and see if that makes your mag hold open happier.
 
Fordean said:
Installing Door holders. Ran 14/2 firealarm cable to door holders for release. Run is about 225 feet at its longest holder. (Holder # 4) ( and includes 1,2,3 holders closer).

Door holder wont hold. Rated @ 24Vdc. @.015 amps.

Have 27.00 Vdc readings but still wont hold.
Click to expand...

You have 27 VDC at the holders?

Did you verify the holders are in fact 24 VDC? We install a lot of 120 volt holders is it possible someone gave you those by mistake?

If you have 27 VDC and they are 24 VDC holders I would be thinking a problem with the closer as mentioned although I don't think the adjustment screw will change the tension only the speed.
 
mgookin said:
Assuming you have self-closing doors with magnetic holdback, check the tension screw on the self-closer.

FL Bldg Code says 3 second minimum for a self closer to move the door from 70 degrees to within 3 inches of the strike (to keep from chopping off hands). Open the door to 70 degrees and let it go; count 1 mississippi, 2 mississippi, etc. and see how your setting is. If it slams too quick, ease off on the setting and see if that makes your mag hold open happier.
Click to expand...

Most commercial door closers do not have a closing tension adjustment. That is a fixed part of the design. You can only control the speed at which it closes. Once it gets to within a few inches of closed, the separately adjustable speed is usually set FASTER so that the door will have enough momentum to overcome friction in the latch, poor fit, etc.

If the closer tension is too strong or the magnetic hold-open is too close to the hinge point, there will not be enough force to hold the door open. This may also happen if the door is very heavy and is installed non-vertical so that gravity is also trying to close it.

Any alignment problems which keep the plate and the magnet of the hold-open from lining up perfectly will also reduce the force available.

Finally, measure the voltage at the most distant coil with all of them energized. If it is too low, it will not meet its force specification.

Bottom line: lots of places to look for the problem, not all electrical.
 
iwire said:
You have 27 VDC at the holders?

Did you verify the holders are in fact 24 VDC? We install a lot of 120 volt holders is it possible someone gave you those by mistake?

If you have 27 VDC and they are 24 VDC holders I would be thinking a problem with the closer as mentioned although I don't think the adjustment screw will change the tension only the speed.
Click to expand...

THey are multivolt. 120 down to 12 volt. Says they are 24 Ac/ or 24 dcv.

Rixson 6t310 is the door holder number.
 
GoldDigger said:
Most commercial door closers do not have a closing tension adjustment. That is a fixed part of the design. You can only control the speed at which it closes. Once it gets to within a few inches of closed, the separately adjustable speed is usually set FASTER so that the door will have enough momentum to overcome friction in the latch, poor fit, etc.

If the closer tension is too strong or the magnetic hold-open is too close to the hinge point, there will not be enough force to hold the door open. This may also happen if the door is very heavy and is installed non-vertical so that gravity is also trying to close it.

Any alignment problems which keep the plate and the magnet of the hold-open from lining up perfectly will also reduce the force available.

Finally, measure the voltage at the most distant coil with all of them energized. If it is too low, it will not meet its force specification.

Bottom line: lots of places to look for the problem, not all electrical.
Click to expand...

These are just hold open, Release at fire signal call. rixson 6t310 cat no.
 
Fordean said:
These are just hold open, Release at fire signal call. rixson 6t310 cat no.
Click to expand...

These are rated at "Holding Force 50-55 Lb" when energized at the voltage for that particular model. They are available in 120AC, 24AC/DC and 12DC models, all under the same base catalog number.
Release at fire call signal just means that the fire call signal must open the drive circuit to all of the hold opens.
If it takes more than 50#, measured with a scale at the point where the plate is installed, to hold the door open, then they will not work.
 
Fordean said:
Would series wiring matter on DC.?
Click to expand...

Series wiring? Are the holders wired in series? They need to be wired in parallel.

When you say "T tapping", are you tapping both conductors and running both the new device? That would be wired in parallel.

If you are just breaking one existing wire, and running a wire from each wire "end" at the cut, that would be in series.
 
Status
Not open for further replies.
Top