Control Power Problem

[help]

I have an NX-8 with two LCD keypads.  Earlier this week at 1am in the morning the keypad started peeping and fire code blinking rapidly.  The service command displayed that a Control Power Problem existed.  I have checked the transformer and I am reading 18.2 VAC at the panel terminals.  I have also checked the battery and I am getting 13.4 VDC at the panel terminals.  I currently have disconnected both power and battery to quiet the system.  I planned to start trouble shooting again today.  What is the voltage AC or DC that i should have at the keyboard terminals?  and what else would you recommend to check?

[ABLE1]

Hello and welcome to the Forum.

First to stop the peeping I mean beeping you just need to enter your code.  Powering down is another way but the code is the easiest.

The voltages you are reading are normal however the panel checks the battery regularly and it seems always in the middle of the night.  If it gets a low reading it will go into trouble.  The voltage at the battery you got of 13.4vdc is the charging voltage.  To test the battery it would best to disconnect the AC power and then check the battery.  The voltage will start to drop.  If the battery is indeed bad it will drop rather quickly.

So how old is the battery??  If it is more than 3 years it should be change regardless.  The battery is designed to last from 3 to 5 years. 

Since you said the Fire light is flashing this could mean something else.  I would suggest first that you power up, enter your code to silence the keypad, and then press * 7 to clear the Fire LED.  Then start checking your smoke detectors for proper blinks.  Depending on unit, maybe about 7-8 seconds between blinks.

Hope that gets you started.

Good Luck

ABLE1

[help]

Thank you for your quick reply,

In my manual it states that if the battery is low the power light on the keypad will flash.  I have no power light at all.  Also the trouble code in the manual states that a control power condition means  "The main power to your system is not on."  I have been in my home about 6 years and replaced the battery about 2 years ago.  Do you think the battery will cause this condition.  I will be back home in a few hours and will try disconnecting the power and checking the battery.  If that is good, what do you recommend to check next.  To confirm that I don't have any problems with my circuit board, what levels should I have at the keypad terminals?

[ABLE1]

Ok,

Power up, AC then Battery.  Enter code to stop trouble.  Do not type * 7 as it will reset and may go back into trouble. (or not)

Check voltage at AC terminals (should be about 18vac)

Check voltage at AUX + COM (should be about 13.7vdc

Check voltage at KP+ and KP- (should be about 13.7vdc

Do you have a 2 wire or 4 wire smokes?? 

If you have 4 wire smokes do you have a do you have a end of line power relay installed??

Your problem is not with the keypad.  It is a power issue.  At some point you may want to start taking one power device at a time off and see if the problem goes away.  When it does then put that wire back on.  If it comes back that would be the cause of the trouble.  Determine what it feeds and go from there. 

If everything is off the board and the problem still exist then you will need to isolate each keypad or other expander's.

Hope that helps.

ABLE1

[help]

Ok,  Tested the battery as you requested it held steady at 12.75 to 12.86vdc for about 30 minutes.  Just to cut that out of the equation I replaced it anyway.  Right now on the control board terminals I have the following measurements.
AC 19.02 VAC
Aux + Com = 13.12 VDC
KP Com + KP Pos = 13.13 VDC
Battery terminals read 13.12 VDC.

With everything on I have still have no power light on the keypads, and in the LCD it states service.  If I try to enter any code it just goes blank for a few seconds and comes back on and still says service.  I will start pulling devices and see if anything changes

Edit:

Oh yea, i do have a 4 wire smoke also with the relay mounted in control box

[ABLE1]

Interesting??  Ok, so what happens when you press * 7 on the keypad??  Does the problem clear and then return??

Has there been a local power outages recently??

ABLE1

[help]

No power outage recently.  Everything has been good for the past six years and no changes to the system.  neither of the two keypads will allow you to enter anything.  As soon as you hit any button on the keypad the LCD goes blank and comes back on a few seconds later and does not allow you to enter any codes.

[help]

So far I have pulled the exterior siren control wires and the smoke control wires with no change

[ABLE1]

Put a resistor across the Bell + & Bell - terminals.

Also a resistor on what ever zone is your Fire zone.

ABLE1

[help]

Already have a resister across the fire zone.  no change wen placed across the bell zone

[ABLE1]

Since you have LCD keypads then do a * 90 and look at the event history.  Go back as far as you need to where all was good.  Then move forward and write down each event in order.  May give a clue as to what is going on.

ABLE1

[help]

It is impossible to hit *90 since the LCD screen goes blank when I hit any key.

Edit:

 Ok I went through each zone and disconnected and reconnected with no changes.  I have disconnected one keypad from the system and the other keypad is operating.  If I hit *90 all I see is the troubleshooting I have been doing, plus alot of open and closing of doors.  nothing significant.  With the one keypad on.  Everything seems to be working with exception of now it has an expansion error.  for the second keypad not communicating with the panel.  I have checked all my smoke detectors and they all have slow beeping ( not peeping ) green lights and no red lights.  On the keypad if I hit *^ and go through the zones it says they are all OK.  Is there anything I can check with the second keypad to get it back operational short of purchasing a new keypad?

[ABLE1]

Since you have two keypads then remove take them off at the panel.  Then pick one and move it to the panel and wire it in right there.  If there is a issue with the wiring or the keypad you should be able to isolate.

ABLE1

[ABLE1]

We are talking too fast.

Take the removed keypad to the panel and connect it there.  Remove the wiring for the keypads first.  See if it works.

Do a power cycle to clear the missing keypad.

ABLE1

[help]

Pulled keypad off the wall, reconnected lines at the control panel and measured 13.10 VDC at the keypad location.  The wires appear to be transmitting power.  Trying to find some scrap wire now to connect the keypad directly to the panel.

Found some wire and connected directly to the panel.  Same result.  When the second one is hook to the panel.  they both go out. and if I hook up only one at a time only the one does not work.  It appears to be a keypad problem.  Is there anything that can be repaired or do you just bite the bullet and replace it.