200 amp 3-phase panel how many miners?

[Yellowlaser]

Hi Guys, I have a 200amp 120/208v 3-phase wye system at my warehouse. Each asic miner uses 3400 watts, how many asic miners can I have?

 

[tthh]

What coin are we mining?

 

[zbang]

Have you asked your electrician?

Also, remember that each watt going in needs to be removed by cooling, so that same 200a feed needs to power the HVAC (and lighting/incidental loads).

 

[Jraef]

200A x 208V x 1.732 = 72kVA of available power.

3400W / .8PF = 4.25kVA per miner required

72,000 / 4.25 = 16 miners.

But as zbang said, you must consider other loads like minimum occupancy required lights, plugs and the MASSIVE amount of air conditioning you will need. That will have to come from an HVAC person. My guess would be 10 miners, assuming nothing else is in that building. So start by telling your HVAC person to size the AC to handle 34kW of heat load for the worst case climate you are in, then see if that will need more than 38kW of electrical power. If it is less, you might be able to squeeze in another miner or two.

 

[electrofelon]

200A x 208V x 1.732 = 72kVA of available power.

3400W / .8PF = 4.25kVA per miner required

72,000 / 4.25 = 16 miners.

But as zbang said, you must consider other loads like minimum occupancy required lights, plugs and the MASSIVE amount of air conditioning you will need. That will have to come from an HVAC person. My guess would be 10 miners, assuming nothing else is in that building. So start by telling your HVAC person to size the AC to handle 34kW of heat load for the worst case climate you are in, then see if that will need more than 38kW of electrical power. If it is less, you might be able to squeeze in another miner or two.

Another thing to consider is that the limiting factor may be in what the POCO provides. I wired up a grow a few years back in a warehouse and the 120/240 three phase "200 amp" service was feed with a 3x15kva bank. I loaded it up to about 50 KVA but didn't want to go much higher.

 

[Yellowlaser]

What coin are we mining?

Bitcoin

 

[Yellowlaser]

Have you asked your electrician?

Also, remember that each watt going in needs to be removed by cooling, so that same 200a feed needs to power the HVAC (and lighting/incidental loads).

I have asked multiple electricians but getting different answers. Some are saying only 9 and others are saying 16. I just don't understand how trained electricians cant figure this out.

 

[Yellowlaser]

Just to provide more context, here's a photo of the panel. https://ibb.co/5rG6w7y

 

[winnie]

I have asked multiple electricians but getting different answers. Some are saying only 9 and others are saying 16. I just don't understand how trained electricians cant figure this out.

Because the problem is poorly defined and different people are including different levels of 'headroom' or accounting for other loads.

You say that the miners each use 3400W. You don't provide the power factor or duty cycle. You don't state if the panel must supply the miners only, or also ancillary loads such as lighting or air conditioning.

Post #4 gives one example calculation. But it assumes non continuous loading. You could also hit 16 if you have continuous loading with unity power factor power supplies.

Depending upon the specifics, 9 to 16 are all plausible numbers. If you are getting a range from different electricians, then you've probably left something critical unsaid.

Jon

 

[Yellowlaser]

These machines will be immersion cooled. We'll be installing a dry cooler but power usage should be minimal. Here an image of the specs for the machine. https://ibb.co/0rZMwGH

Even though it stayed 3068watts, I checked with a power meter and it runs closer to 3350

 

[winnie]

The input current rating is 20A, that is what an electrician is supposed to go by. So even though you measured 3350W you need to use a value of the 20"208 = 4160 VA per unit.

I presume you are going to run these 24x7, so you are limited to 80% loading on your feeder circuit. Your feeder is rated 208 * 200 * 1.732 = 72kVA, * 0.8 = 57.6 kVA. At 4160 VA per unit that limits you 13 units.

Jon

 

[Another C10]

21 ? .. ok maybe 16.8 miners, Just keep adding them and see what the amp probe tells you. Voltages fluctuate during the day so there really is no specific accurate number, just build as allowed.

 

[zbang]

At 4160 VA per unit that limits you 13 units

Agreed.
However just looking at that number still doesn't account for removing the heat of the machine from the room they're in. While the individual machines might be immersion-cooled, the heat still has to be moved outside the room, and that takes energy. At 3400 watts, each machine would need almost a ton of cooling; that itself could be 10KW of load. In the winter, you might get away with fan-cooling, but not in an LA summer, unless, of course, the machines will operate at over 35c (which we also don't know).

This is the kind of thing that needs coordination between an electrician and the HVAC designer so they both know the electrical/heat loads and how to move that heat around. We're just guessing based on incomplete information.

 

[kwired]

Another thing to consider is that the limiting factor may be in what the POCO provides. I wired up a grow a few years back in a warehouse and the 120/240 three phase "200 amp" service was feed with a 3x15kva bank. I loaded it up to about 50 KVA but didn't want to go much higher.

If you told POCO what the load was going to be and they only put a 45 kVA bank when you have 50 kVA of load - I think it is their problem.

That said it likely handles it in most cases, though something that is 24/7 continuous loaded (and in summer months) may not quite be good enough.

 

[electrofelon]

If you told POCO what the load was going to be and they only put a 45 kVA bank when you have 50 kVA of load - I think it is their problem.

That said it likely handles it in most cases, though something that is 24/7 continuous loaded (and in summer months) may not quite be good enough.

I wasn't very clear, but that service was existing. We also brought in a new 1200A 480 service.

I think we are always supposed to inform POCO of load additions, but many people don't and assume they have full NEC service size capacity.

 

[kwired]

I wasn't very clear, but that service was existing. We also brought in a new 1200A 480 service.

I think we are always supposed to inform POCO of load additions, but many people don't and assume they have full NEC service size capacity.

With my farm loads I have found is best to inform POCO of significant load additions. The customer may not be happy there is charges from POCO but they also usually get some credits based on loading. Wait until next time load is added and even more capacity is needed they don't get any credits related to the first load increase. This generally only applies to loads that run for longer periods. Add a load that is bigger but somewhat limited demand and it may not matter at all.