Design PCB for High AC Amperes

Hello to all. First sorry for my poor Englsih.
I would like to design a PCB that there is 16 relays on it that each one is 220vAC 25A.
How much should I take the diameter of tracks on the PCB for this Ampere, and any good tips if somebody has for my design, Please.

25A needs a very wide trace. Somewhat less wide if 2 oz copper is used.

What relays are you using? You will need a driver for the coil. On this relay card I offer, a TPIC6C595 shift register is used to sink current thru the relay coils.

What connector are you using for the 25A current? Need something pretty hefty.
These Phoenix connectors are rated for 30A for example.

250v and 25 amps, that's sounding more like a contractor.

I'm using JQX-16F(T91) as a relay and ULN2803 as driver.

So much useful.Thanks.

I would also do double tracks, aka, top and bottom in parallel with via stitching.

But what on earth are you driving? 16 x 25A x 230V* = 100kW! That is MASSIVE! I would not even think about switching that through a single PCB. And where will you get a 400A connection? Because most countries I know forbid mixing connections to separate fuses/circuit breakers in a single unit/PCB.

*230V because English is not your native language aka not American so assuming European.

250v and 25 amps, that's sounding more like a contractor.

Contactor. The contractor might be the person who installs it!

Contactor :confused:


I'm using JQX-16F(T91) as a relay and ULN2803 as driver.

So much useful.Thanks.

That uses spade terminals so connection to the PCB for the high current path is not needed.
Just use cables.

PCB tracks are a bit thin for 25A as you want >>4mm^2 of copper in the current paths where feasible to have that, and inch wide tracks are not a good use of PCB. One old method is to hand solder copper rod over (or under?) >2mm copper PCB tracks. The next size up, for [lots] more amps than suits 4mm^2, is to bend and saw copper rod of rectangular cross section to exactly fit each main track. I don't think you need to resort to that much hacksaw work for 25A; wire snips will do, to collect the copper core from 30-Amp mains cable pulled out of a skip. Have a look at it, and make any serious power tracking at least wide enough to attach that.

Or better still, do without tracking for the big currents as the post above suggests. That will need a robust big box as >=25 Amp cables can be semi-rigid and would immediately kill someone or cause trouble if knocked loose and flapping around near your work table. Make sure first that you have had a look at a few examples of fat cable for 30 Amps though, as "cooker" cable is a big size jump up from "13 Amp" appliance cable. If in any doubt at all, ask a properly qualified electrician to at least inspect your piece before connecting it to mains, and it might be illegal not to.

See comments above regarding illegality of getting 100 kW without a serious industrial connection. You usually have to pay extra for a sparky who has done the extra qualifications for industrial connection as opposed to domestic.