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Security & Fire Protection Systems/replacement for Rollins alarm power transformer


Our Rollins V alarm system has worked for many years but the plug in power supply transformer recently failed. My manual does not provide the output DC voltages nor amperage but there are 4 terminals, for Red,Black,White,and Green wires. Number on the circuit board inside the transformer is 700B89. Transformer was made in Malaysia 196-8729 M. I am having trouble locating a replacement. I suspect power goes to the main panel and also to the battery backup which is 6V  4.5Ah, battery  UB645. How can I find specific information on transformer requirements? Maybe I could use 2 separate transformers each with 2 terminals to supply the main panel board?

Hello Ken, and thanks for your question.

In a nutshell, there are two ways to determine a replacement transformer.

The first is that most transformers have their ratings printed on them. So have a look at the outside of the old transformer. Look for markings such as 12 VAC 40VA, or 16.5 VAC 20 VA. Something like that.

The second way is to look at the hookup diagram inside of the control panel. 99% of the time, the ratings for the transformer will be listed there.

By the way, there should be only two wires connecting the transformer to the control. Oftentimes, installers will "double-up" wires from the common 4-conductor cables, so that 2 conductors go to each terminal in the control.

Once you find the rating, you can Google "alarm transformers" and get dozens of online vendors.

The important rating is the voltage, which should be an exact match #i.e., 12 VAC or 16.5VAC#. For the Volts per amp rating, listed as VA, you have latitude. If you can't find an exact match, choose one with a higher VA rating. It won't harm your system.

Now, if you can't find the specs from the transformer or hookup diagram, please write again. We'd have to try to identify the exact make and model of the alarm panel. Rollins, you see, is not a manufacturer of alarm controls. Other companies produce them and brand them for Rollins.

So again, you'd have to look both at the hookup diagram AND at the main board. You'd be looking for information like DSC #with numbers behind it#, or ADEMCO or Vista #again with numbers behind it#.

Send me that information, and I'll be able to look it up for you.

I hope this helps!

Best Regards,


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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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