Thread: Workshop Layout Any Ideas Suggestions

NP is 'Not Permitted'. The table goes on for several pages and the explanatory notes are at the bottom.

I would be more a little more reluctant to use maximum demand limitation for a sub-circuit at a place like a Men's Shed because it's not possible to predict usage patterns so accurately. With a home shed it is entirely reasonable to assume either that a single person will be working in there (hence certain machines won't be used concurrently) OR that the person who had the installation put in will be working there in a group situation, and can tell people what machines they can or can't use together. That isn't really a valid assumption for a Men's Shed.

That said, the worst that would realistically happen at the Men's Shed if you used the maximum demand limitation method is that the breaker would trip if you used too many machines on one circuit. Wouldn't have to happen too many times before signs popped up telling people what equipment combinations trip the breaker =)

You might find that your equipment is rated at 15A because of the high inrush current at startup. My air compressor is only 10A rated but will happily trip a 20A breaker at startup if another 10A load is running on the house power circuit when it cranks up. I'll be putting it onto a 16A circuit shared with the DC in my shed, just to give it headroom.

By the way, I should make it clear that I'm not an electrician nor do I have formal electrical training. I just know my way around Australian Standards. I have had this discussion in depth with three qualified electricians though, one of whom specialises in electrical system design (no longer on the tools; design work only) and none of them have been able to find a flaw in my logic.

In terms of thumbsuckers needs, perhaps the message to take away is

the standard advice that a 15A outlet needs its own circuit is related to the use of "standard" household 3 core wire. Heavier wire would allow more than one 15A outlet on the circuit, but how many sparkies would have that heavier wire in their van?

thumbsucker maybe should run something heavier than 20A wiring into the shed. Assuming that the DC is running at 10A (like BobL's does), and his table saw is pushed to it's max and draws 15A like BobL's, then thumbsucker could easily trip a 20A circuit.

And I agree that plugging and unplugging machines from a 15A or 20A circuit is not a good idea. Perhaps along with each machine's on/off switch, each machine should have it's own isolation switch on a sub-board in the shed. My thinking is that when processing timber, the DC will always be on, but only one or at most two other machines will be active at the same time. and this is the best way to limit the total electrical load.

Originally Posted by ian

In terms of thumbsuckers needs, perhaps the message to take away is

the standard advice that a 15A outlet needs its own circuit is related to the use of "standard" household 3 core wire. Heavier wire would allow more than one 15A outlet on the circuit, but how many sparkies would have that heavier wire in their van?

Not quite. Heavier wire and higher rated circuits may allow the concurrent use of more than one 15A machine on the same circuit. Standard wire and a 16A circuit may allow the installation of more than one 15A point with the proviso that you won't be able to run more than one 15A machine at a time on that circuit without tripping the breaker. And you need to find a sparky who understands that such an installation is permitted by AS3000 Wiring Rules.

YMMV

Originally Posted by Moph

NP is 'Not Permitted'. The table goes on for several pages and the explanatory notes are at the bottom.

I would be more a little more reluctant to use maximum demand limitation for a sub-circuit at a place like a Men's Shed because it's not possible to predict usage patterns so accurately. With a home shed it is entirely reasonable to assume either that a single person will be working in there (hence certain machines won't be used concurrently) OR that the person who had the installation put in will be working there in a group situation, and can tell people what machines they can or can't use together. That isn't really a valid assumption for a Men's Shed.

Makes sense.

That said, the worst that would realistically happen at the Men's Shed if you used the maximum demand limitation method is that the breaker would trip if you used too many machines on one circuit. Wouldn't have to happen too many times before signs popped up telling people what equipment combinations trip the breaker =)

That's already happened with some gear but for the following reason.

One of the shed admins questioned whether some gear was really 15A. One of the shed sparkies measured the running current and seeing as they were drawing less than 10A put 10A plugs on them. Of course the current being drawn was not measured under load and when put on a 10A circuit every now and then they popped the 16A 10A circuit breaker. Before long we had that list you mentioned above.

You might find that your equipment is rated at 15A because of the high inrush current at startup. My air compressor is only 10A rated but will happily trip a 20A breaker at startup if another 10A load is running on the house power circuit when it cranks up.

Yep that happens with my compressor as well.
This is a side issue but if the motor is appropriate the use of a VFD with slow starting can get around this problem

I'll be putting it onto a 16A circuit shared with the DC in my shed, just to give it headroom.

That assumes either your compressor or DC are running at any one time.
I sometimes find it useful to be able to run them at the same time when cleaning down a machine as it limits the spray of dust into the rest of the shed.

Keeping it really moron simple and in terms thumbsuckers needs.

The electrician uses a 4mm wire for the 20 amp circuit.

The electrician installs 1x 20A circuit breaker combination safety switch at switchboard with 4mm2 cable from switch board to a standard plate 20A outlet in garage wall.

I assume this 20 amp outlet plate has two power points so I can plug in two machines.

I can then turn on the dust extractor let it power up using most of the 20 amps as it gets up to speed after which it should draw less amps then once the dust extractor is going I can run the tablesaw.

Without tripping the 20 amp circuit.

Are you still intending on getting the Felder DC?

What is your TS HP?

If it is the same or similar HP as the DC the TS will have a similar start up current to the DC.

The current rating on the breaker is only one aspect of whether the start up current will trip the breaker. The other is the type of breaker - a standard household breaker should be able to cope with some over current for a couple of seconds.

Dust Extractor - Motor 50 Hz, 1.5 HP (1.1 kW) (401-240)

Sliding Tablesaw - Motor 50 Hz, 4.0 HP (3.0 kW) S6/40%

Combo Planer-thicknesser - Motor 50 Hz,4.0 HP (3.0 kW) S6/40%

Bandsaw - Motor 50 Hz, 3.5 HP (2.5 kW) S6/40%

Originally Posted by thumbsucker

Dust Extractor - Motor 50 Hz, 1.5 HP (1.1 kW) (401-240)

Sliding Tablesaw - Motor 50 Hz, 4.0 HP (3.0 kW) S6/40%

Combo Planer-thicknesser - Motor 50 Hz,4.0 HP (3.0 kW) S6/40%

Bandsaw - Motor 50 Hz, 3.5 HP (2.5 kW) S6/40%

It probably won't matter which way around you do it.
If you are worried about start up currents the dust extractor is likely to have a lowest start up currents and highest free running current so you should probably turn the WW machine on first and then the dust extractor.

The only machine that is going to need constant full power is the DC.
When the other machines start they might hit 50-60A for a fraction of a second but even the 4HP machines will draw less than 10A when free running.
My 3HP BS draws only 1.8A free running, the 3HP Belt/Disc sander about 2A when free running.

I have a quick fix for your workshop send all your tools to me then your problems is solved
Regards Michael

Originally Posted by thumbsucker

Dust Extractor - Motor 50 Hz, 1.5 HP (1.1 kW) (401-240) -- longer term you will most likely find that this is undersized. Given you are wiring the garage from scratch, my suggestion is that you plan for a constant 10A or greater load for the dusty. (10A would coincide with a generic 2HP dusty.) I think that Felder can supply their DEs with single phase 4 or 5 HP motors (= approximately 13A or 16.5A draw)

Sliding Tablesaw - Motor 50 Hz, 4.0 HP (3.0 kW) S6/40% -- max current draw will be on start up and when ripping at maximum capacity.

Combo Planer-thicknesser - Motor 50 Hz,4.0 HP (3.0 kW) S6/40% -- max current draw will be on start up and when thicknessing at maximum width and cutting depth.

Bandsaw - Motor 50 Hz, 3.5 HP (2.5 kW) S6/40% -- when used to resaw at maximum capacity, the current draw is likely to be a constant 11A.

so I'm estimating that the maximum concurrent draw into the garage will occur when resawing and that this load is likely to exceed 20A.

For design prudence, I think you should include a compressor in your calculations. And your next question will be what size compressor?
If used to drive a 16 or 18 gauge brad nailer (very handy for building jigs) and a 23 ga headless pinner, a small 1 to 1.5 Hp unit would be fine, but if you are thinking about spray finishing or driving an air sander, then a bigger unit will be required.

Lastly, don't forget about hand power tools (sanders, routers, etc) and lighting. Will these run off the existing 10A GPO, or also be connected to the new circuit?

Originally Posted by thumbsucker

Keeping it really moron simple and in terms thumbsuckers needs.

The electrician uses a 4mm wire for the 20 amp circuit.

The electrician installs 1x 20A circuit breaker combination safety switch at switchboard with 4mm2 cable from switch board to a standard plate 20A outlet in garage wall. -- I'm not sure this is a wise "instruction" to give a sparky. This mob http://www.olex.com.au/eservice/Aust...013%202014.pdf suggests (page 67) that under some domestic circumstances, a 3 core 4mm cable might be rated as low as 16A. If it were me I think I would be asking for something like a 25 or 30A circuit to the garage, split (via a panel in the garage) into separate circuits. The separate circuits might simply be a single or double 15A power point.
Circuit 1 -- the dusty.
Circuit 2 -- the bandsaw and table saw, and future air compressor.
Circuit 3 -- the thicky / jointer combo, router table and some general 10A outlets for hand power tools and the pedestal drill.
Circuit 4 -- future plug in air conditioner / space heater.

I think I'd keep the general shed lighting and task lighting on the existing 10A GPO. That way if you trip the high current circuit, you will still be able to see what you're doing. But I'd also add one battery backed emergency light so if the street supply trips -- an event that would appear likely in most parts of eastern Australia over the next two summers -- you can see well enough to exit the garage.

I assume this 20 amp outlet plate has two power points so I can plug in two machines.

I can then turn on the dust extractor let it power up using most of the 20 amps as it gets up to speed after which it should draw less amps then once the dust extractor is going I can run the tablesaw. Without tripping the 20 amp circuit. -- as noted above I think the bandsaw will be your hungriest machine (in terms of current draw.)

Originally Posted by BobL

It probably won't matter which way around you do it.
If you are worried about start up currents the dust extractor is likely to have a lowest start up currents and highest free running current so you should probably turn the WW machine on first and then the dust extractor.

I think this is the wrong approach. Typically, once the initial machining of rough sawn timber to dimensioned wood is complete, WW machines are only used intermittently. Turn saw on, make a cross cut, turn saw off. Add a DE's start-up time into the equation and it's all too likely that the 5 second cut will be made without turning the DE on. IMO, given that the DE is in a sound enclosure, it's better to leave it running.

20A is probably too slim IMO but I don't know that 4 new circuits and a garage sub-board are justified - that's a big investment in a property that he doesn't own, and the owner may well not permit it. It depends how long he anticipates staying there, I guess, and the relationship that he has with the landlord.

If I were in thumbsucker's situation, I would:

1. Rely on the existing lighting circuit for ambient lighting.
2. Run task lighting off the 10A GPO that presumably already exists in the garage. Just jerry rig it so you can take it with you if you move.
3. If there is room in the house switchboard, install 2x 16A RCBOs with new circuits as follows:
   Circuit 1: 2x 15A outlets (air compressor and dust extractor; non-concurrent use)
   Circuit 2: 3x 15A outlets (tablesaw, planer-thicknesser and bandsaw; non-concurrent use)

It's still far from an ideal setup but is relatively cheap and should give solid performance. It's also likely that 2.5mm cable could be used as that's generally rated for 16A or more, so the cost saving there helps offset the cost of the additional circuit. The sparky would also need to be prepared to adopt the limitation of maximum demand method as discussed earlier in this thread.

Also consider ceiling-mounted GPOs rather than wall mount. Can work well and avoids conduit running down the face of the wall.

Lots of conflicting / alternative advice suggestions regarding electricity circuits. If I do one I off another.

I like the idea of ceiling-mounted GPO.

I do not nor will I ever do the kind of work that requirers a brad nailer or a compressor. We had a compressor at Uni and its only use was to blow dust around.

I have 4 10amp power points in the workshop more then enough for jerry rigged lighting and hand held power tools.

The machine manufacturer states that I need a 20amp plug and a minimum of a 20 amp circuit per machine.

This is not my house and I do not want to spend thousands on electrical circuits. no matter how good my relationship with the owners are.

Its going to be one circuit and one power point thats it.

I am going to have to move machines around and I will have to use an extension lead but that is the price of having such a space.

I have a friend who pays like $250 per month for a dirty shared space in an old factory out Footscray way.

Many people would kill to have a private double garage space like mine.

I have been watching these youtube videos of this guy in Germany Marius Hornberger who has like a tiny space looks like 1/2 a car space, he could NOT fall over if he tried, he is so jammed in, tools, wood, machines, projects & himself.

Originally Posted by thumbsucker

The machine manufacturer states that I need a 20amp plug and a minimum of a 20 amp circuit per machine.

Ah okay - not sure if that was mentioned earlier in the thread (if so I missed it) - but if that's the case then you must (per AS3000) install a 20A circuit as you proposed.

Originally Posted by thumbsucker

Its going to be one circuit and one power point thats it.

You might experience overload tripping if you're running your table saw and dust collector off that single 20A circuit. Best off running the dust collector off one of the existing 10A GPOs and reserving the 20A just for your woodworking machines IMO.

Originally Posted by thumbsucker

Lots of conflicting / alternative advice suggestions regarding electricity circuits. If I do one I off another.

I do not nor will I ever do the kind of work that requirers a brad nailer or a compressor. We had a compressor at Uni and its only use was to blow dust around.

Fine.
Though brad nailers and battery powered drill/drivers are very useful when building jigs.
And 23ga headless pins are more than useful when it comes to attaching moldings to furniture.

Originally Posted by thumbsucker

I have 4, 10amp power points in the workshop more then enough for jerry rigged lighting and hand held power tools.

The machine manufacturer states that I need a 20amp plug and a minimum of a 20 amp circuit per machine.

This is not my house and I do not want to spend thousands on electrical circuits. no matter how good my relationship with the owners are.

Its going to be one circuit and one power point thats it.

understood.
1 x 20A circuit with one 20A point plus an exta-heavy duty extension cord which you move from machine to machine. And the dust collector will be connected to the existing 10A GPO.