Security & Fire Protection Systems/EN1550R


QUESTION: Hello Dave. I have a question about the same EN1550R system. How do you lower the volume of the siren on this system. There is no display on the keypad and the instruction booklet doesn't mention anything about adjusting the volume. I have one of those big loudspeakers with this system which scares the whole neighborhood.

I appreciate any suggestion on this. Thank you.

ANSWER: Hello Sasan, and thanks for your question.

On burglary alarms, there is no built-in volume control for sirens or bells. That's because the whole idea behind having a siren is to attract the attention of residents and passersby. This requirement was established early on in the use of burglary alarms -- before there were viable means available to transmit alarm signals to either a police station or a monitoring center. In fact, the standard was always to mount the bell or siren outside, and in a location that was visible from the street.

Since the late 1970's, with the advent of digital communicators that used the regular telephone system to transmit alarm signals, the need for a siren as a means of communicating an alarm is lessened -- but not eliminated. For example, if a telephone line were compromised (as burglars often attempt), and there were no siren, there is nothing to limit the amount of time that a burglar would be willing to spend in a burgled premise.

Anyway, to solve your challenge, there are a few choices, and these assume that your system is monitored for alarm signals.

1. First, if your siren is outside, you could replace it with a strobe light. Of course, this would need to be visible from the street.

2. An outdoor siren can be relocated inside the building. In a residence, this would typically be in the attic, facing a roof or ridge vent so it's not muffled too much.

3. Replace the siren with one that has an internal volume control. Here's an example:
(Note: I don't endorse products or companies -- this is offered only as an example.)

I hope this information helps you to balance the need for a loud audible alarm with your desire to not scare the neighborhood. If you have follow-up questions on this, please write again.

Best Regards,


---------- FOLLOW-UP ----------

QUESTION: Thank you so much, Dave. The system in place is an old one which is no longer monitored and we don't have a landline, either. The system is not connected to a battery, but all the wiring is in place. Since we don't need the siren any longer, can I just disconnect the loudspeaker? Would that cause any problems if I remove it?

Thank you again for your time.

ANSWER: Hello again ...

Yes, you can disconnect the siren in the control panel. I don't know off the top of my head which terminals are for the siren, but there should be a hookup diagram on the inside of the cover.

You only need to disconnect one of the two wires, and make sure the bare end can't short against anything by wrapping it in electrical tape.

Once you do that, the ONLY noise from the alarm will come from the keypad. Keep in mind that since your system isn't monitored, there's very little chance that if a burglary occurs, that anyone will hear the keypad and notify the police.

I hope that helps!

Best Regards,


---------- FOLLOW-UP ----------

Wall outlet
Wall outlet  
QUESTION: Thanks very much. Your answers are very helpful. I have one more question for you, if you have time. Underneath the control panel I have a device which is connected to the wall outlet and it feels very warm as if it is about to burn. Can I disconnect this as well without harming the electrical system of the house? I have attached a picture as well.

Thanks again for your time.

Thanks for your kind words!

The picture you sent is of the system transformer. This is what powers the alarm system, and keeps the backup battery charged. You mentioned that you don't have a battery installed, though, so this is the only power source for the alarm.

You can disconnect it without harming anything in your home's electrical system, but if you do, your alarm will be completely dead.

It's common for the transformer to be warm to the touch, and from the photo, I can see discoloration to the plastic case from the heat. This too is common for transformers that have been in service for several years.

If you want to remove the transformer, you'll have to remove the screw that's holding it (and the outlet cover plate) in place. After you remove the screw, simply unplug the transformer.

Thanks again,


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Dave Neuweiler


The design and application of burglary and fire systems for homes and businesses. Helping alarm owners understand how their system works. Helping to troubleshoot false alarm problems. Questions about monitoring issues.


Over a quarter century in the industry. Experience in installation, service, and monitoring centers. Training manager for a national protective services company; director of education and training for a national trade organization for for alarm dealers.


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