Q: I am replacing an alarm panel that used 2.2 K End-0f-Line Resistors (EOLR) with a newer panel that specifies 2 K EOLR. Can I keep the existing door contacts with their slightly different built-in EOLRs? I would rather not have to replace them.
A: I will first premise this answer with you should always try to use products that are specified by the manufacturer. Also, I would recommend to double check with the specific manufacturer as to what they recommend. However, in this case and to help ease your concerns you should be ok as long as your cable runs are not to long. Remember, you always have to consider the resistive load of cabling, specially in a supervised circuit.
All EOLRs have a resistor tolerance of typically 5 – 10%. Taking the worst-case scenario of 5% tolerance then the range for a 2k EOLR would be 1.9K to 2.1K and on a 2.2K EOLR it would be 2.09K and 2.13 K. So you can see that there is a small common range in the EOLR tolerance ranges and they could actually be the same value.
Q: I have a customer that is upset with the numerous false alarms they are getting from their residential ionization smoke detector. I could relocate the smoke detector, but I would rather find a solution without the extra labor.
A: I would suggest that you look at replacing the unit with a photoelectric smoke detector. They are typically more stable in a home environment and will still give a good range of smoke detection, though in a slightly different spectrum.
Always make sure that the smoke detector is one that is specified by the panel manufacturer. This will help you not to void the UL listing of the panel for smoke detection.
