Simplex 4006 nac help

I own a simplex 4006 and on nac 2 I have a simplex 2901-9838 on a simplex 4903-9101 strobe plate along with a simplex 4051 horn on a simplex 4050-80 light plate. When I hookup the 4051 with the light plate, it gives me a trouble and won’t let any devices on that circuit signal. When I remove the 4051 with the light plate, the 9838 with the strobe signals. The 4051 has a polarization diode behind it and the light bulbs ohms rate is .02. On nac 1 of the panel, I have a simplex 4906-9127 smart sync true alert and will only signal the horn instead of both the horn and the strobe. Can someone please let me know what I can do to make them work correctly?



When the trouble is on the system for that NAC and is in the display press ENTER then NEXT. I bet you will find the Stat=SHRT which means the circuit is shorted. If the lamp is just a socket without a supervision diode in series with it, that is the problem. The panel is smart enough not to turn on a circuit in short condition.

An incandescent lamp has a very low resistance when the filament is cold. The resistance increases tremendously when the filament is hot. That is why bulbs usually burn out when first turned on. That is when the current draw is the greatest.

To operate the 4906-9127 smart sync device the NAC has to be set to QALERT in programming. Use the link below to get the instructions.

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So what do you suggest I do?

Disconnect the light to see if the trouble clears. If it does the circuit should work. Then add a diode IN SERIES with the light socket with the cathode (banded end) towards toe negative of the NAC.

I added information to my previous post about the SmartSync A/V.

Okay I’ll go try that. The truealert is set to qalert

Try a different strobe intensity setting. There might be a loose connection around the selection plug. The flash tube could have come loose from the connectors on the circuit board in shipping. The strobe section could just be bad.

I’ll try that. I’m getting a short on the nac even though there is a diode

I’m still getting a trouble even though there is a diode without the bulb

Remove the devices from the circuit one at a time until the trouble clears. The supervision voltage across the circuit should be around 22.7 volts DC. You can compare the voltage on the circuit in trouble to the circuit that is not in trouble.

I still can’t get the trouble to clear

With no NA devices connected and with a 10K resistor connected to the B+ and B- there is still a trouble?

Press ACK to get the trouble on the display. Then press ENTER and then NEXT.

Complete this statement Stat=_____ .

What is the voltage across the 10K resistor across the circuit?

I got the 4051 with the light plate to work

I’m thinking I can’t get the strobe to charge because the truealert is a newer device and the panel must output the older smart sync code

I can’t agree. To my knowledge the TrueAlert non-addressable SmartSync code has not changed.

This chart is on page 3-6 of the 4006 manual linked in a post above. It shows your device is compatible. As far as I know this is correct.

Do you think the 10k resistor on the truealert has something to do with the strobe not charging?

No. The device doesn’t care where the resistor is. No matter the distance relationship between the device and the resistor they are in parallel. The resistor only draws 2.4 mA = 0.0024 amp.

Okay, I just don’t understand why the strobe isn’t charging because I’ve tested it off site from the panel with the smart sync cube and it charged then

OK. It could be the NAC. The strobe is charging as long as there is power on the circuit. The strobe flashes when the power to the NAC is shut off for about 20 milliseconds. Try switching the programming and the devices between the NACs. If NAC1 is the QALERT change it to NAC2 and test it. Maybe the NAC you are using is not inserting the sync pulses correctly. Does the strobe flash at all? Like one flash when the system completes a reset?

No it doesn’t flash at all

We are getting down to the limit of what can be determined with one panel and one NA device. The problem is either the panel, the NA device, or both. It takes an oscilloscope to check that the panel NAC is operating correctly, or another known good NA device. Your NA device can be tested on another panel that produces SmartSync signal or a Smartsync Control module. Another way to test the NA device is to apply 24 volts to the strobe for 1 to 2 seconds and then remove the voltage. The loss of voltage should cause a flash.

The fact of the burned in ground fault indicates the panel was subject to some sort of severe electrical overload. There could be other damage that is effecting other circuits in the panel. However even if the panel is not correctly injecting the sync pulses on the NAC, the strobe should at least flash once when the NAC shuts off.