It seems to me that the relays on the NAC module are not turning on. You should see the voltage and polarity change when the system changes from normal to alarm condition. That is the first item we have to figure out. Look on the NAC module for jumper wires or 0 ohm resistors being installed or missing between solder pads 15 to 16 and 29 to 30 on the NAC module. In an unmodified system those jumpers should be there. (see picture) Also check the 556-880 control module to see if diode D25 is in or cut out. It will be there in a standard system and removed in a modified system. If these components are missing it indicates the system is modified. (Sorry no picture but D25 is a large diode near the PC edge connector.) One of the modifications that requires these components to be removed is adding a march time module.
[attachment=0]2076-jumpers.jpg[/attachment]
The voltage across a NAC will be lower than the power supply voltage when the circuit is in normal condition. The supervision circuit has additional resistors that are in series with the EOLR to make a voltage divider circuit. Other components on the card use these voltage differences to determine if the field wiring is normal, open, or shorted. The 2001 NAC modules were designed for a 15K ohm EOLR, but a 10K will probably work. When a NAC is in alarm the supervision circuit is disconnected and the signal power supply is connected to the circuit in the polarity that allows the horns to sound.
I don’t know what meter you are using but all will indicate a polarity reversal. On an analog meter the pointer needle will go in the opposite direction when the leads have not been moved but the polarity has changed. A digital meter will display a - in front of the digits to indicate negative polarity.
Let’s hold off on the march time module until we get the basic panel situation figured out. Adding the MTM will take adding some wires and modifying the control and signal modules.
I figured the 2001-2076 (556-874) was the NAC module supplied with the system. Most systems of this type were supplied with that card.
Here are some basic diagrams on how a NAC works.
The first diagram is when the system is in normal standby condition. The field wiring is connected to the supervision circuit that checks for the wiring integrity. This is the circuit that lights the card TROUBLE LED and sends a trouble signal to the CONTROL MODULE.
Notice that each horn contains a diode. When the circuit is in normal condition these diodes are reverse biased so the supervision current cannot flow through the horns so has to flow through the EOLR.
[attachment=2]NAC-normal.jpg[/attachment]
This diagram is what happens when the system goes into alarm. The field wiring is connected to the signal power supply in a polarity that allows the horns to sound.
In this diagram the polarity is reversed and the diodes in the horns are forward biased. This allows the signal power current to flow through the horns so they make noise.
[attachment=1]NAC-alarm.jpg[/attachment]
My 2001 demo panel has a march time card in the system and D25 is cut, as well as several resistors on the NAC card. I had to run a jumper wire from the march time card’s output to the relay control inputs on the NAC card. The resistors on the NAC Card – when cut do those disconnect the relay controls from the constant alarm output from the control card so the march time card can work?
It is possible that D25 was cut on his panel because if I pull the march time card out of mine and reconnect D25 then it works. However I needed jumpers from the main control card to the NAC card inputs to make it work though.
That is good information. It gives a direction to start troubleshooting. This could be a faulty control module (556-880) or a faulty signal module. It could also be a burned circuit board trace on either module or on the motherboard.
I will post again with some test points to determine if the control module is working correctly.
Quick question, normal operation is for the red LED on the zone module to flash when put into alarm. When the ACK button is pushed the alarm LED then goes steady on. Is that how your zone is working when activated? This is the first control module test.
Another question. There is a set of jumpers on the motherboard labeled JW4 through JW12. Working completely from memory I think these are on the left end of second row of sockets. All of these should be there. Are they? Just being sure nobody sabotaged the system.
The ack button is broken off but when pushed with a wire insert when in alarm the led does NOT go steady also when I was figuring out the panel i shorted something out which created some smoke from the control module
Maybe this helps
Letting the smoke out explains a lot. That control module might be toast. At minimum the ACK switch needs to be replaced, however it probably has burnt circuit board traces and/or damaged components. There are a few listed on Ebay.
Smoke could also have come from the motherboard in the area of the control module. Both sides should be examined very carefully for damaged circuit traces.
A 2001 system uses a number of buss conductors that are common to all card slots. These distribute power and control signals between the cards. In a unmodified 2001 a zone module sends an alarm pulse to the control module on the “D” buss. This activates relay K1 on the control module which then operates K2 on the control module.
Relay K1 causes a +24 volt output on PC pin E (solder pad 109) and connects 0 volts to PC pin C (“C” buss, solder pad 5). This 0 volt connection is used by the signal module to activate the relays.
When the ACK button is pushed 24 volts is disconnected from relay K1 and it drops. The +24 volt output on pin E and the 0 volt output to pin C shuts off. The ACK button also momentarily places +24 volts on the “8” buss which the zone module uses to change the LED from flashing to steady on. This is the switch that is broken on your control module.
Relay K2 is latched on until reset. It causes a +24 volt output on PC pin 5 (solder pad 105). This output is not bussed to the other cards but is available for special functions. It does operate the on until reset alarm relay on the motherboard next to TB5.
When the reset button is pushed +24 volts is momentarily disconnected from the control module relays K1 and K2. +24 volts is also momentarily disconnected from the “A” buss which is the resettable power to all the modules in the panel.
So in an unmodified 2001 the control module should cause these outputs.
Measuring from system common (0 volts) available on on TB5 terminal 5 or 6 and on TB6 terminals 4, 5, or 6.
When the system is put into alarm +24 volts at solder pads 105 and 109.
+24 volts should drop from pad 109 when ACK is pushed. But your ACK switch is bad.
+24 volts should drop from pad 105 when the reset button is pushed.
Measuring between solder pads 109 and 5.
When the system is put into alarm +24 volts should be between solder pads 109 and 5. This should drop out when the ACK button is pushed. But your ACK switch is bad.
These are the voltages and operations that will take place with a good control module.
K2 is the power transfer relay. It should energize when normal power is on. It drops out on brownout to transfer the system to batteries. That relay is fairly hefty. They seldom go bad. It is possible that when the smoke was let out one or both of the regulator chips was damaged. Those are LM317K adjustable regulators in TO3 cases. These are commonly available at parts houses (except RS).
Radio Shack is a very slight possibility on the relay. K2 has a 24 VDC coil and RS has very few available in 24VDC. All have to be ordered.
Ok but I forgot to mention that it came with no relay in k2 I inserted a random relay I had which is 120vac which i know won’t work for that.
And thanks so much for putting time into helping me I really appreciate it!
OK. Let’s go back to the tests I outlined several posts back.
(The solder pad numbers are the places on the motherboard where special application jumper wires go.)
So in an unmodified 2001 the control module should cause these outputs.
Measuring from system common (0 volts) available on on TB5 terminal 5 or 6 and on TB6 terminals 4, 5, or 6.
When the system is put into alarm +24 volts at solder pads 105 and 109.
+24 volts should drop from pad 109 when ACK is pushed.
+24 volts should drop from pad 105 when the reset button is pushed.
Measuring between solder pads 109 and 5.
When the system is put into alarm +24 volts should be between solder pads 109 and 5. This should drop out when the ACK button is pushed.
Since there are no special jumper wires going to the signal module location, have you tried it in a different card slot? Maybe one on the top row (J3 to J8)? Don’t use J2, it is a little different for special application cards. It is not wired to operate a signal card.
OK, so we have our on until ACK and on until RESET voltages. This is good.
This control module could have come from a system that had march time or some other coded signals. That is fairly common. When coded signals are used there is a diode that has to be clipped on the control module. That disables the steady on control signal to the NAC modules. The coding card produces the on-off signal to code the NAC outputs.
The part that is cut is D25. Check the picture below. On this card D25 is orange. Some of them are gray. Some are black. Notice that the one in the picture has the top lead clipped. This module came from a coded system. Sometimes people just clip the top lead while others cut the diode out completely. Check your module for this and reply. This will cause there to be no voltage between pads 109 and 5.
NAC modules only have to be wired special when march time or other coding is being used. For continuous ring (non-coded) signals the modules are just plugged in and it works.
Well, this is a mystery. The way this works is that in a standard system the relays on the NAC card get the + side of the 24 volts from the resettable +24 on the A buss. When the system goes into alarm the control module turns on -24 volts which goes to the NAC module on the C buss. The relays on the NAC card get their -side of the 24 volts from the C buss. That is how the NAC card relays are activated in a standard system. That - side of the 24 volts goes out of the control module through D25. That is why it is cut in a coded system.
I think we have looked at this before but I want to double check. There are two wire jumpers or 0 ohm resistors (depends on the age of the card) on the NAC card that are normally in but are cut for special operations. They go between numbered points 15 to 16 and 29 to 30. Those connect the +24 volts from the A buss to the relay coils.
Verify on your NAC card whether these jumpers are in or cut.
[attachment=0]2076-jumpers.jpg[/attachment]
As I recall you said you have a march time card. Plug the march time and signal card in. The LED on the march time should flash for about 1/2 second about every 6 seconds. IF the jumpers are in on the signal card, the relays on the signal card should pulse with the march time card LED. Click click. Putting the system in alarm is not needed, it should just happen.
I found a substitute for the K2 on the motherboard. It is an NTE R14−11D10−24P. These are available from many sources and are around $10. That should get the system to switch to normal power. Right now it is running on the battery charger. I’ll dropbox the datasheet so you can see the picture.
I just remembered something. There was a manufacturing modification to march time cards.
When I wrote>>
IF the jumpers are in on the signal card, the relays on the signal card should pulse with the march time card LED.
That applies to march time cards 2001-3044 / 556-249 of revision E and earlier.
In revision F and later boards the 0V pulses come out of a different pin on the card connector and have to be wired to the motherboard to make it work.
