240v 20a questions

[Noideron]

I have a wood shop that has 240v 20a circuits hardwired into the panel. I see most people building systems build them to 240v 30a or 50a, has anyone built a system with 20a restrictions on a 240v system?

We are currently BIAB Brewers on our propane fired system. Our standard batch size is 5 US Gal. I am interested in a heated mash tun, but it is not a necessity. Winters here in WI make it hard to hold a standard cooler at temp for a full mash.

I am in the early stages of evaluating the feasibility of switching to electric. Both my father and I have previous electronics experience( he was a shop teacher for 30+ years and I have built more than 1 computer and wired new circuits in a home) so DIY is not an issue.

Any tips on components that will help save amps, but still make for an enjoyable brew day, are appreciated.

 

[wilserbrewer]

Batch size?

 

[Noideron]

5 US Gal current. I figured bigger batches were going to be the first limitation with the reduced amp rating.

 

[wilserbrewer]

Simple solution would be a 3500w induction cook top.

240v 20a is quite a bit of power considering it will power a 4500w element. Certainly 10 gallon capable with reasonable heating times IMO.

If you have been brewing outdoors thru Wisconsin winters, you are going to love [emoji173]️ electric brewing indoors.

 

[doug293cz]

You could just limit yourself to a 4500W element, which would draw about 18.75 amps. Wouldn't be able to run a pump on the same circuit, so no pump outlet in the panel (unless you want to use two independent circuits to feed the panel.) You could also go with a lower wattage element, but I don't know what kind of choices are available.

Brew on

 

[jaroporter]

20A is easily enough for double that batch size, but it will come down to how you design your system. insulation is obviously your friend, but especially boiling with a hood rather than a wide open pot (or even the lid part on). for context, i can get a hard boil on a maxxed out keggle with a 3kw element at half power. even at max 3kw would only draw bout 13A.

alternatively, ditch the insulation and that boiler makes a killer rad to heat your shop!

 

[processhead]

If your shop is in a unfinished space, you might consider wiring a new dedicated 30 amp circuit for brewing purposes.
Should be an easily doable and affordable project with a minimal amount of self-study and planning for a DIY type.
Having a 30 amp circuit really opens up a lot of brew system possibilities without limitations or compromises.

 

[Noideron]

I would have to install an additional sub panel. The 200a service to the house is full, as well as the 100a dedicated shop panel is full. I would have to add a sub-panel to the shop to make a 30a service. The machines that are currently hooked in the 20a service could be damaged by current in a 30a circuit.

Unfortunately the wife is not too keen on the additional cost of wiring a new panel. The budget for the panel is tight already and that would definitely break the bank (even though it is only a couple hundred for a spa panel install).

 

[SleepyCreekBrews]

I have a 30 amp circuit for my 10 gal rig but never turn it up past 20 amps.
As a rule of thumb, you shouldn't really be using 20 amps off a 20 amp circuit tho ... 17 would be a reasonable max IMO tho. ....and you could brew 10 gal batches with that power.

 

[SleepyCreekBrews]

I would have to add a sub-panel to the shop to make a 30a service. The machines that are currently hooked in the 20a service could be damaged by current in a 30a circuit.

Tools don't use any more power than they need , you could connect a table saw to a 50 amp welder circuit (appropriately wired of course) and an it would still draw the same current.

For the benefit of others reading this, be advised that 20A circuits come in both 120VAC and 240VAC

 

[processhead]

I would have to install an additional sub panel. The 200a service to the house is full, as well as the 100a dedicated shop panel is full. I would have to add a sub-panel to the shop to make a 30a service. The machines that are currently hooked in the 20a service could be damaged by current in a 30a circuit.

Unfortunately the wife is not too keen on the additional cost of wiring a new panel. The budget for the panel is tight already and that would definitely break the bank (even though it is only a couple hundred for a spa panel install).

There is no risk to any of your machines by operating them from a 30 amp circuit. You only have increased the maximum load that can be operated on the circuit.
By replacing the existing 240 volt/20 amp breaker in you panel with a 30 amp breaker AND installing AWG 10 wire to an appropriate receptacle, you can operate anything you were running previously, as well as any other equipment up to the 30 amp capacity of the circuit.

 

[itsnotrequired]

There is no risk to any of your machines by operating them from a 30 amp circuit. You only have increased the maximum load that can be operated on the circuit.
By replacing the existing 240 volt/20 amp breaker in you panel with a 30 amp breaker AND installing AWG 10 wire to an appropriate receptacle, you can operate anything you were running previously, as well as any other equipment up to the 30 amp capacity of the circuit.

this can be true but is not a hard fast rule. many pieces of electrically operated equipment have requirements on the maximum upstream ocpd rating. so if the owner's manual for, say, a table saw indicated a maximum 20 amp upstream fuse/breaker, it would technically be a code violation to operate on a 30 amp circuit, even with #10 wire. the table saw in this example will physically work just fine under normal conditions but could have problems in an overload condition, by the larger breaker not tripping when it should.
it is also not clear what type of existing receptacles the op has but they may not even be able to accept #10 wire.

i would say that in general, likely not a problem to go from 20 amp to 30 amp breaker/conductor but it is installation-specific.

 

[processhead]

Agree. However unlikely, the equipment manual trumps all.
That said, I would expect equipment requiring protection of a specific circuit breaker to also be hardwired into that circuit breaker. Equipment wired with a service cord and plug could inadvertently be plugged into the wrong socket too easily.

 

[SleepyCreekBrews]

Equipment wired with a service cord and plug could inadvertently be plugged into the wrong socket too easily.

Not necessarily, almost all receptacles are different for the various circuit loads , a good example is the 240v/20A, 240v/30A, 240v/50A receptacles and plugs. Even 120v/15A and 120V/20A are different

 

[processhead]

Not necessarily, almost all receptacles are different for the various circuit loads , a good example is the 240v/20A, 240v/30A, 240v/50A receptacles and plugs. Even 120v/15A and 120V/20A are different

True. Different receptacle types do offer some control over appliance use.

 

[itsnotrequired]

also note that if you have a 30 amp branch circuit, code requires 30 amp receptacles. it is acceptable to use 15 amp or 20 amp on a 20 amp circuit (provided there is more than one receptacle on the circuit, else a 20 amp circuit requires a 20 amp receptacle) but at 30 amp, can't have any 20 amp receptacles. ironically, you can have 40 amp or 50 amp receptacles on a 40 amp circuit (with more than one recep on the circuit) but once you jump up to 50 amp circuit, all receptacles need to be 50 amp.