Shorepower Circuit Monitor?

[abraxus]

Can anyone tell me if there's a simple plug in device that will show me power usage on a 240v circuit?

I know there are ones for individual sockets/appliances but I'd like to able to plug something into a socket and get a reading for the draw on the whole circuit.

The only reason I want it is to save me having to remember what I've got switched on and then totting it all up before turning things like the microwave on without tripping the breaker. I usually have a good idea in my head of how things stand but a gauge of some kind would be far easier, especially when there are other people onboard who have a tendency to turn things on willy nilly.

 

[VicS]

Can anyone tell me if there's a simple plug in device that will show me power usage on a 240v circuit?

I know there are ones for individual sockets/appliances but I'd like to able to plug something into a socket and get a reading for the draw on the whole circuit.

The only reason I want it is to save me having to remember what I've got switched on and then totting it all up before turning things like the microwave on without tripping the breaker. I usually have a good idea in my head of how things stand but a gauge of some kind would be far easier, especially when there are other people onboard who have a tendency to turn things on willy nilly.

I think you would either have to wire something in to the incoming powers supply or use something based on a current transformer on the incoming live conductor.

 

[abraxus]

I think you would either have to wire something in to the incoming powers supply or use something based on a current transformer on the incoming live conductor.

Thanks Vic, it would seem from my brief searching that you're right, I was optimistically hoping for something simpler.

 

[Ian_Edwards]

I use a simple amp meter wired into the 230volt supply (as part of the boats AC switch panel). I know that most marina supplies are rated at around 16amps and will trip if more than 16amps is supplied for a more than a few 10's of seconds.

So I take a look at the amps being drawn as indicated on the meter and from experience and the rating (watts) of the dialectical appliance,I know how close I am to tripping the supply.

eg
water heater 2 to 3amps
100amp battery charger 7 or 8amps when delivering 90 to 100amps to the domestic battery bank, dropping to just 1 or 2 amps when the batteries are on float charge.
5amps for a 1kW fan heater
about 10amps for the microwave when cooking
about 8amps for the electric kettle

The rest is mental arithmetic! But that doesn't mean I don't get wrong .

 

[FullCircle]

How about something like this?


http://www.ebay.co.uk/itm/Digital-B...quipment_ET&hash=item1e7ce4502e#ht_4566wt_954


Actually, as my boat is at the end of a long pontoon, we get considerably less volts than 240, so the amps go up as the voltage goes down..... I have measured 168v at our input before now. So something that shows volts and amps as above is quite useful

 

[abraxus]

Thanks guys.

FullCircle, that looks just the ticket. Do you just wire it in to the pos and neg mains leads at the shore power panel?

 

[Noahsdad]

Think you may mean Live and Neutral wires.
My interpretation is that you also have to connect the transformer ring which goes around the shore power cable and also connects to the display.
My Mandarin is a bit rusty though!
Seems cheap enough to give it a go, be interested in one myself!

 

[abraxus]

Yes, you're right.

My Mandarin's not so good either so I was wondering about that, thanks for the heads up.

 

[FullCircle]

Yes, you're right.

My Mandarin's not so good either so I was wondering about that, thanks for the heads up.

对不起，我什么都不知道关于普通话

 

[rogerthebodger]

Look here http://www.ebay.co.uk/itm/Digital-A...d=100005&prg=7041&rk=1&rkt=5&sd=310703000806&

No Mandarin required

 

[VicS]

Think you may mean Live and Neutral wires.
My interpretation is that you also have to connect the transformer ring which goes around the shore power cable and also connects to the display.
My Mandarin is a bit rusty though!
Seems cheap enough to give it a go, be interested in one myself!

The wiring diagram is self explanatory Mandarin or not.

Connections to the live and neutral for the voltmeter

Connections to the CT for the ammeter. The CT is fitted around one conductor only, not around the whole cable.

The Chinese diagram shows it fitted the the neutral conductor.
Roger's link shows it fitted around the live conductor.
Either will do equallly well

 

[abraxus]

OK, I'm no electrical wizard but can manage simple things.

So in summary, is this as simple as conecting to the live and neutral wires, and fitting the transformer ring around either, at the entry point of these wires at the shorepower panel?