Interfacing on/off current sensor to M1 input

[BDHall]

I noticed the following on CR Magnetics web site (advertised as a new item) for applications that require an on/off indication of current flow. This unit has a low fixed trip point (fully on at 350ma). They have three flavers of this model as well as a model with a larger opening for the wire, and the price looks pretty good. Forgive me if this is old news but it is the first time I have noticed this model and it looks very interesting to me.

I was hoping that perhaps Spanky and others might comment on interfacing this sensor to an Elk M1 input (zone).


CR9321-ACA AC output

CR9321-NPN Transistor output NPN

CR9321-PNP Transistor output PNP

http://www.crmagnetics.com/newprod/Product...ProdName=CR9321

Thanks!
Brian

 

[FrankMc]

Hi Brian

Would have thought you could use the NPN version with the Elk ...Since the Elk has a pull up resistor on its input,normally the input would be high and the npn current detector would pull it low once it detected the trip current..
I think you would have to programme the zone input as a straight on/off rather than an alarm input...Dont have an Elk so my terminology may be incorrect..

HTH
Frank

 

[Spanky]

You will need the NPN version and you will have to play with the current Resistor which you will connect to +12VDC. It says that it can sink 120 Milliamps full on. You can read the analog voltage level at the input with the ASCII string commands or see the value in keypad menu 8, 6. You can write some Rules to have various trip points with the analog voltage level.

 

[BDHall]

You will need the NPN version and you will have to play with the current Resistor which you will connect to +12VDC. It says that it can sink 120 Milliamps full on. You can read the analog voltage level at the input with the ASCII string commands or see the value in keypad menu 8, 6. You can write some Rules to have various trip points with the analog voltage level.

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?

Thanks!
Brian

 

[will40]

You will need the NPN version and you will have to play with the current Resistor which you will connect to +12VDC. It says that it can sink 120 Milliamps full on. You can read the analog voltage level at the input with the ASCII string commands or see the value in keypad menu 8, 6. You can write some Rules to have various trip points with the analog voltage level.

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?

Thanks!
Brian

Hi Brian,

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.

Works everytime.

$15 for CT
$28 for RIB

Good luck.

Will

 

[BDHall]

[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?

Thanks!
Brian

Hi Brian,

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.

Works everytime.

$15 for CT
$28 for RIB

Good luck.

Will

Will,

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)

Thanks!
Brian

 

[will40]

[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?

Thanks!
Brian

Hi Brian,

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.

Works everytime.

$15 for CT
$28 for RIB

Good luck.

Will

Will,

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)

Thanks!
Brian

Sorry, can't help you with burden resistor on that NPN model with DC output. I would bench test before hooking up to my Elk.

I used the CR3110 AC out put. The burden resistor chart with equation to limit secondary to 10VAC is located on their datasheet:

http://www.crmagnetics.com/pdf/3110.pdf

Will

 

[tmbrown97]

The washer may be a little more difficult due to very low and sometimes almost no current during parts of the washer cycle.

FYI, while this may seam a little daunting at first, many models of washers are pretty easy to interact with... I know I had to troubleshoot mine once (Kenmore Elite model)... Handy thing is, once you open the cover, there's generally a sheet of paper with full schematics. I know there was one wire on mine that had power any time there was any type of cycle running. It'd be very easy to throw an extra $5 120V relay off that wire straight into an Elk zone without any extra sensors. Mine uses all simple connectors so I could throw my relay in-line in a way it didn't cut or interfere with the washer in any way - and could be untraceably removed if the machine needed service. Using that, I could just run a 2-wire into a zone on the elk and know exactly when the washer finished a cycle. You could probably do the same with the dryer, using another 120V relay and a resister getting 3 states out of one 2-wire zone, and have this all done for under $15.

 

[BDHall]

-->QUOTE(Todd B @ Sep 1 2008, 02:54 PM) [post="95609"][/post]

The washer may be a little more difficult due to very low and sometimes almost no current during parts of the washer cycle.

FYI, while this may seam a little daunting at first, many models of washers are pretty easy to interact with... I know I had to troubleshoot mine once (Kenmore Elite model)... Handy thing is, once you open the cover, there's generally a sheet of paper with full schematics. I know there was one wire on mine that had power any time there was any type of cycle running. It'd be very easy to throw an extra $5 120V relay off that wire straight into an Elk zone without any extra sensors. Mine uses all simple connectors so I could throw my relay in-line in a way it didn't cut or interfere with the washer in any way - and could be untraceably removed if the machine needed service. Using that, I could just run a 2-wire into a zone on the elk and know exactly when the washer finished a cycle. You could probably do the same with the dryer, using another 120V relay and a resister getting 3 states out of one 2-wire zone, and have this all done for under $15.
[/quote]

Todd,

Thanks for your reply.

I have been using the relay approach as you described for a while on my dryer and considered doing as you described to the washer. My reason for wanting to use the current switch is that I will most likely at some point be changing to a new front load washer and possibly a matching dryer and I wanted a "non invasive" approach to avoid any possible warranty issues.

Brian

 

[electron]

If you are just trying to monitor a washer, most of them have a little light (especially front loaders). It's extremely easy to monitor this with the M1 without having to open your washer. Just use a cds photocell. There is a tutorial in the how-to section.