Electrical Repair Questions? Ask an Electrician for Answers ASAP
For now assume the other stuff is negligible. We have less than 2 kW of lights running, heating will be disconnected, A/C will be run by us(and we can account for those loads, but just hypothetically assume we have 2 60a 208v circuits dedicated to A/C. There's nothing else in the building except a garage door opener that might pull 2kW at max(but I doubt it).
What level of 30amp circuits would we be allowed to add?
24/7, actual load is somewhere between 12 and 26 amps.
Yes, most but not all drops are active at the same time.
I can easily calculate out what we can run on our incoming 600 amps. What I'm trying to figure out is what code allows us to build because we may be in a situation where we need more drops but put less load on each one as time goes on, but if we don't build for it up-front it is more expensive to add it later.
Ok, thanks. When you have equipment such as this operating in an almost continuous manner, you calculate it at 125%.So, the number for the service load calculation goes up at 6.2 x 125%= 7.75kwWith just guesstimate of AC and lighting, you probably have 20kw.Leaves you with 195kw at most (not counting anything else in the building)So, you could have 25 drops of your maximum.You have to calculate at the maximum usage point that the equipment is capable of operating at any point in time.
Just like on a stove, the entire stove is 6000 watts even though you rarely use it all, only a small portion is normally operated.
But it is capable of the total, so it must be accounted for in the calculation..
Any other electrical will take away from that number as well. Like water heating, outdoor lighting, convenience receptacles, other lighting or more AC needs for heat dissipation etc.
Ok, but what does the code allow? What if the maximum load we expected from one device was 12 amps / 2.5kW, would we be able to run more and still meet WA electrical code?
It is based on what is in place, not what is expected, but what it is capable of consumingSo, if you have half of your posted 6.2kw in place for operation, then you would have double the amount available, once all existing electrical is accounted for and calculatedThat is why it is critical to know what the equipment nameplates state as the wattage.That is what must be used for the determination.
If there is no equipment in place, you can place the drops for possible future movement of equipment. If there is nothing there to operate, there is no load at the time.
Just specify each drop at 2.5kw for your installation.
That is the NEC.
So so long as we have nothing there at the time of inspection, we can run whatever we want?
The reason I am asking is we want to run extra drops to accommodate future possible needs, with full knowledge that plugging in all of them could run us over limits and cause the main breaker to blow. We just can't perfectly anticipate our future needs, but we were told (by a non-electrician) that code only allows for a 10% net overage.