Mamac Current Sensing Switch/Switches, CT-800/CT800 NEW on Ebay

[beelzerob]

So, the 2 things I'd like most to monitor (that I'm not already) are my water heater and my well pump. Both are 220v, of course.

So I need to feed 1 hot wire through this switch, right? Probably with the water heater, it will easily exceed 1 amp when in use, so I won't need to add any loops. The pump is variable speed, though, so a couple loops through that would probably be a good idea.

But is there any safety issues involved in disconnecting the wire from either the water heater or circuit breaker panel and running through this thing and then reconnecting it? (assuming I turned the power off, of course). It's not one of those "it must be torqued to the exact amount" sort of connections is it?

 

[beelzerob]

or i guess whether the washer and dryer are still going... would be good for a whole-house reminder that the dryer is finished and get the damn clothes out of the dryer already, wife.

What would be the easiest way to use this to monitor a dryer? Would it be better to disconnect the dryer wire from the circuit breaker panel and feed it on there, or rig up a 220v plug to put inbetween the dry plug and the wall outlet?

 

[electron]

I don't see how you can install this in the breaker panel without violating some major codes, and causing other logistical issues. Modifying a 220V cable would probably not be safe and/or cost effective.

For now, I use a door contact mounted on the drum, or if your dryer has a LED, you could monitor that. I wanted to use one of these to monitor my dryer as well, but I realized that my dryer was 220V AFTER I bought them

Only other methods I can think of (which do involve taking your dryer apart, but that's easy) are to monitor the power going to the motor, or the power to the buzzer, assuming it is sensitive enough.

 

[beelzerob]

I don't see how you can install this in the breaker panel without violating some major codes, and causing other logistical issues. Modifying a 220V cable would probably not be safe and/or cost effective.

Well, what I meant was to disconnect it at the panel, pull the wire out, separate out a hot cable from the jacket, slip the sensor on it, and then put the wire back into the panel and reconnect it to the breaker....so the current sensor would not actually be in the panel.

I know there are other ways to monitor when the dryer is and isn't running, but someone mentioned using these mamac's to monitor their dryer, and I was wondering how they did that.

 

[electron]

JohnW monitors his dryer, but he has a gas based dryer if I am not mistaken, so no 220V to deal with.

 

[mustangcoupe]

Well, what I meant was to disconnect it at the panel, pull the wire out, separate out a hot cable from the jacket, slip the sensor on it, and then put the wire back into the panel and reconnect it to the breaker....so the current sensor would not actually be in the panel.

I believe this would still be a code violation. As your cable is no longer double insulated going into the panel. Or if you put the sensor in the panel you then have LV in the pannel if you somehow mount it inside the panel.

The only way I see you can accomplish this which may still be a code violation is use a junction box and cut the cover so that the top of the sensor with the LV terminals is now exposed outside of the box. and make any changes to the 220 V line inside the box.

 

[jwilson56]

JohnW monitors his dryer, but he has a gas based dryer if I am not mistaken, so no 220V to deal with.

Yes I have a gas dryer

 

[Steve]

Couldn't you disconnect the 220v cord from the dryer, separate 1 leg from it and slip it through the sensor then wire it back up? Most dryer cords I've seen have each conductor in a separate sheath that you can peel away from the others (like this). If you have one where all the conductors are in one sheath you can simply replace the cord??? Seems like that would be the simplest and safest route??

 

[beelzerob]

The only way I see you can accomplish this which may still be a code violation is use a junction box and cut the cover so that the top of the sensor with the LV terminals is now exposed outside of the box. and make any changes to the 220 V line inside the box.

I'm leaning towards this way now, since it would seem to be the safest, least exposed way..but it'd also be expensive. 2 X 220v plugs aren't cheap.

 

[Squiddy]

I like the idea of taking a wire off on the dryer side and monitoring it there. That's what I am going to do providing the back of the dryer isn't too hard to get off. There is probably a small junction box built into the dryer down where the cord goes in. I will have to go take a look.

 

[SteveQ]

FYI I am monitoring my dryer with a current sensor. Be aware that the current sensor may switch ON/OFF many times when the dryer is running because the heating element turns ON/OFF. So depending on what you are trying to do, an OFF signal from the sensor does not mean the dryer is finished.

Steve Q

 

[mustangcoupe]

FYI I am monitoring my dryer with a current sensor. Be aware that the current sensor may switch ON/OFF many times when the dryer is running because the heating element turns ON/OFF. So depending on what you are trying to do, an OFF signal from the sensor does not mean the dryer is finished.

Steve Q

maybe add more windings to the current sensor so that just the motor running will trip your input on your controller. This will be the least current during any cycle. and the motor will always be running....

 

[jwilson56]

FYI I am monitoring my dryer with a current sensor. Be aware that the current sensor may switch ON/OFF many times when the dryer is running because the heating element turns ON/OFF. So depending on what you are trying to do, an OFF signal from the sensor does not mean the dryer is finished.

Steve Q

maybe add more windings to the current sensor so that just the motor running will trip your input on your controller. This will be the least current during any cycle. and the motor will always be running....

These particular sensors have a 1 amp trip point so keep that in mind. So two windings will essentially make that that a .5 amp trip point.

 

[upstatemike]

FYI I am monitoring my dryer with a current sensor. Be aware that the current sensor may switch ON/OFF many times when the dryer is running because the heating element turns ON/OFF. So depending on what you are trying to do, an OFF signal from the sensor does not mean the dryer is finished.

Steve Q

maybe add more windings to the current sensor so that just the motor running will trip your input on your controller. This will be the least current during any cycle. and the motor will always be running....

These particular sensors have a 1 amp trip point so keep that in mind. So two windings will essentially make that that a .5 amp trip point.

I did some basic tests. The sensor triggered fine with a 60 watt light bulb (1 winding) but not with a 40 watt bulb. This suggests the sensitivity is actually a bit lower than 1 amp.

 

[SteveQ]

[/quote]
I did some basic tests. The sensor triggered fine with a 60 watt light bulb (1 winding) but not with a 40 watt bulb. This suggests the sensitivity is actually a bit lower than 1 amp.
[/quote]

I'm not sure the sensitivity would be the same for a 120V circuit compared to a 220V dryer. I am using 2 turns; I can't fit a third turn through the transformer.

Steve Q