Hello Fluksonians,
I am looking to install a kilowatt meter or two but i am wondering about their amp rating.
I have seen talk of a 50 amp kilowatt meter connected to a pulse input which i think would be fine for my solar circuit (solar is 4.5kW).
But if i put one in my main circuit i am worried that a 50 amp unit may not be suitable. My mains supply breaker is an 80 amp breaker.
Not that i would ever want to be drawing 80 amps but i am thinking this 50 amp kilowatt meter may turn to smoke before the main breaker trips if ever there is a fault.
Has anyone else put a kilowatt meter in their main circuit? Does the meter amp rating need to be higher than the main breaker rating?
I am thinking i will either have to put in a 100 amp meter which will be difficult due to its size and the lack of space in my switchboard or just change the main 80 amp breaker for a 50 amp breaker.
My switchboard currently has an 80 amp main breaker, a 16 amp breaker (solar), 2 x 20 amp breakers (ovens), 5 x 16 amp breakers (power points) and 2 x 10 amp breakers (lights).
If i did put in a 100 amp meter i would have to swap out my 5 x 16 amp breakers (power points) and 2 x 10 amp breakers (lights) as they are all 2din safety switches and replace them with 1din safety switches. Gets expensive.
Any suggestions? I may just go with the 50 amp meter on the solar and use a current clamp for the main consumption circuit. I would have liked to have the greater accuracy of a kilowatt meter but i think the cost is going to be too high for a minor improvement.
Does the main breaker switch one or three phases? If it is switching just one it must be a rather thick cable...
You 'must' replace same for same. If a switch is rated at 80A then any thing in series with it must be equal. Sub circuits can be less.
Bazzle
Thanks for the replys.
@Bazzle, i thought so but its good to double check. I think i will order a 100amp current clamp and use it on the main circuit as it seems the simplest and least expensive.
@Gebhardm, it is just a single phase. I'll have to have a look at the wire thickness the next time the sparky takes the cover off. Might actually try and grab a photo for me to keep as a reference, it will save me getting the cover off if i need to jog my memory on the wiring layout.
Actually received the Flukso unit yesterday and did the initial config last night. It still needs to have its inputs connected but so far so good. :)
I'm running a 100amp kWh meter on my sub-board no problem and had bought two 50amp ones but decided against using them. I've also ordered another 100amp one to go on the house, after the main 80amp switch. The 100's have better screw points and you're always safer with an over-rated device than an under-rated.
But to fit the new meter in I will need to have a small extra board put in because of the lack of space.
Just for the technology of the current clamps: The 50A variant has a characteristic to linearly transform up to 75A into a proportional voltage (nevertheless the setup in the FLM will then show just "peak" as with 50A the ADC maximum is reached); there is a safety mechanism built in that prevents the clamp from vaporizing - and to be serious: 230V by 80A equal 18,4kVA; that would be a somewhat huge consumer (an fully operational electro oven plus a vacuum cleaner plus a hairdryer at the same time make "only" 15kW...)
With respect to the wire thickness: the 50A clamp fits up to 10mm diameter wires...
I ended up using the 50amp clamp, tried getting a 100amp one but not available from Aussie distributor.
The installation all went well with the 50amp clamp, now the ruthless energy reduction can begin. :)
If i even get close to maxing out the 50amp clamp then something else is very wrong.
Mind you, when someone runs the microwave, dishwasher, clothes dryer and electric kettle at the same time it certainly produces a spike.
As there is not enough room in my switchboard for a power outlet I am powering the Flukso via an extention lead from a nearby power socket. I am planning on installing a switchboard rail mounted 12 volt DC supply. This is the one i am getting Powerbox PBAMR1-12, it is the 12 volt model.
The good thing with the DC transformer is that then all things Flukso can be hidden away behind the switchboard distribution facia to avoid tempting theft or vandalisim.
A few weeks ago i came home to find the switchboard door wide open and all the breakers switched off. Somebody must have thought it would be funny. Checked my server log and it occured around 3:30pm. So it was a broad daylight attack on the castle. :(