[I finally got around to ordering a couple of the CR Magnetics CR9321-NPN (Transistor output NPN) which is a current switch designed to provide on/off indication of current flow. I believe the CR9350-NPN (larger window) and the CR9380-NPN (Split Core - I ordered one of these also) are electrically the same as the CR9321-NPN.
I was wondering if anyone has one of these in use with an elk zone (input)?
I will start experimenting with this soon but I thought I would check first to see if anybody is already using this particuliar current switch with the Elk and if so, what value resistor was used?
This model looks interesting. Where you looking to monitor and report a variable load?
I wanted to monitor my AC condensor for on/off and used a CR Magnetics model CR3110 on one phase with burden resistor from chart, and used a Functional Device RIBTELC low voltage optoisolate relay to pick an Elk zone.
I extended the CT secondary 60' using CAT5 to my Elk panel and located the RIB in the cabinet.
$15 for CT
$28 for RIB
Thanks for your response.
I do not need to monitor a variable load, I just wanted an on/off indication of current flow. I am looking at monitoring my dryer first, then a washer and water heater. I expect the dryer and water heater to be pretty easy. The washer may be a little more difficult due to very low and sometimes almost no current during parts of the washer cycle. I think a retriggering timing function may take care of the washer issues. For now I want end of cycle indication for washer and dryer, and the ability to monitor the amount of time the water heater is on so I can look at my operating cost for it.
My main concern now is getting the value of the burden resistor correct for interfacing the sensors transistor output to the Elk's input expander cards. What chart were you refering to that you used for selecting your burden resistor?
I thought maybe someone was alreading using this sensor with the Elk. If I do not here from anyone using this sensor I will get in to this as soon as my dryer relocating/rewiring project is complete, which I hope will be tomorrow. (Attics are still very hot in Texas)