ESBN Maximum Import Capacity

I'm pulling in an average of 11kW most nights between charging batteries and one of 2 evs so I presume adding a rectifier isn't going to help as my supply is limited to ~12kW?

When you get up past 11Kw, I'd personally be a little nervous about the heat at the termination contacts in the main CU.

The old question - "Is this safe and worth the risk.."

12kW @ 230v is only 52A, so you have another 10A spare

The ESB SLA for a 12kVA MIC is no more than 52A continuous 😁

Shelly power monitors and you can get an addon that adds temp sensors

I'm paying for 12kva and by God I'll use it.

I sit at 12kw for 3 hours every night the last 4 years

This might be going off the original thread - but it's an interesting topic, one that I've thought about myself a fair bit. I'm not a spark, but I'd be very cautious of running close to max on a consumer board for an extended period of time. Maybe we need a new thread as it's generated a lot of comments in the past.

I have a vague recollection that this changed in the last few years (allowing up to 268v?), but traditionally your supply was always 230v +/- 10% , so in theory you could get anything from 208 - 253v and still be within SLA. To take ECO's case above as an example, drawing down 18Kw at 230v might be fine at 78A, but if the voltage was say 215v that day, you'd have to draw 83A (18000/215) to get your 18Kw - which technically could blow your fuse. If it was 210v, you'd be looking at 86A. To be fair, generally voltages in an area are fairly stable, but it's worth remembering.

Aside: Knowing ECO from a long time here, I'd say he has it well sorted, I'm just using him as an example to highlight that people should be aware of the risks. it's a pain in the hoop to get the main fuse replaced by ESB.

Definitely an interesting topic. Our smart meter started smoking last year in the middle of the night. Esb networks took responsibility for it and replaced the meter cabinet, smart meter and compensated for smoke damage in adjoining room. We were pulling 12kva most nights with car, house battery and dishwasher, washing machine..afterwards I added a temp sensor to our meter cabinet. I can see even in dept of winter the cabinet temp rises by 5 degrees over our 3 hour consumption window. Actually have an esb networks designer due to call tomorrow as Ive concerns about our supply..it's a looped connection to our neighbors which folks on here reckon won't be 12kva at all even though that's what our networks contract says we have. Apparently to get it upgraded we may need to dig our drive up and neighbors which won't be happening as they just had theirs tared last summer.

I was never to bothered about the connection but the fire spooked the crap out of us. Woke in the middle of the night with nest smoke detector in the a joining room. Fire brigade said whole house would have gone up in smoke if we didn't notice. The found the meter cabinet smoking when they arrived as we couldn't find anything on fire in the house.

Id hate to think what would have happened if our meter was inside which it is in lots of older houses.

Meter was taken away for examination but was too damaged to find a root cause. The fire brigade electrician and first networks engineer on site both reckoned the neutral on the smart meter was not tightened to torque requirements.

I'm all for maximizing tarrifs but we are certainly more cautious about it now.. we reduced the grid limit on our zappi so we don't pull as high continuous and also dont bother with the dishwasher now and washing machine at night.

Interesting to see what networks say on site tomorrow but probably will be rescheduled with the flooding today

Cheers

Mick

This is my typical voltage drop at crazy o'clock

Been there, well almost, due to loose neutral.

Luckily you can just about see the temp sensor in there that alerted me of something being wrong.

Whole board was replaced after, with a metal one 😂

Re voltage drop vs current, most devices are current limited anyway so whatever the voltage was it wouldn't / shouldn't exceed the pre defined current limit. Interesting point re temp probe, any recommendations on where to put it?

Woulddn't this be dependant on the infrastructure coming into the house? I would imagine a house sitting underneath a 20KV line with a small spur to the transformer would differ to a house 100m away from the mainline sharing a transformer with another house.

Does that mean that some of those 5 other houses are also on the EV rate? : ) To cause such a drop or that you are just one of the furthest away from the transformer - or both? (No such thing as a stupid question, they tell me..)

Following up on this, I certainly would not recommend people off their own bat blasting their theoretical max import limit without doing a survey of your infrastructure to see is it safe. Is your consumer boards rated for these loads? Is your wiring/tails have the capacity to take these loads? Everything tight etc etc

Here are some Flir Infrared photos I took at some of my gear under full load. I suppose what I am saying if you put in the correct sized equipment you can go close to the limit. I have a number of limits set, the Zappi that keeps it below 80Amps for the main incomer and my inverter is limited to drawing 60Amps. My Zappi is set before my Inverter so is grid side.

This is my Anti Islanding unit and this was the hottest I could find of all my wiring, what’s hot here are wires going into the contactors not the breakers which are rated for 63Amps. I have the current limited going through this to 60 Amps, so this is its limit and can’t go any higher. Is this too hot?

This is my meter cabinet and this is under 18kW load for about an hour at this stage….no issues here Max temp about 25degs

This is my consumer board what’s highlighted here is the trip for my Zappi, the other hot spot is the doorbell transformer!, max temps in my board are only about 35degs maybe

This is my 15kVA Quattro under max load…have yet to see that thing struggle or put out any heat. It has three big fans and in a cool garage so it operating in ideal conditions.

Finally these are the battery cables, charging at 200Amps (53V) but divided by 3 so each battery here is taking about 3.33kW so well below their capacity. Hardly any heat off them