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Setting up my electrical.

Matt Matt

Cast Iron
Joined
Jul 11, 2014
Location
Oshawa
Okay I'm kinda new to getting certain voltages to my machines. I'm just starting out building my home machine shop. I'm not a stranger to high voltage machines. I work using them all day long in an industrial environment but 600 V is already there.

But now I'm going to embark on setting up single phase 240 V 40A to my future shop. From the disconnect I'm planning on dropping one outlet (for a welder with voltage and amp display) and splicing to a 240 5 hp Rotary phase(with starting caps, running caps, magnetic start and 3 V/A displays). Then I'm planning on running it into 240 V three phase 30A (with 15 amp fuses) disconnect and dropping one outlet and spliced to a 240V to 600V transformer. After the 600 V transformer back into another 600 V 30A (with what size fuse do I need here?) disconnect and dropping another outlet. Each machine will be fused accordingly (on the back of the machine) to the motor specs unless of course equal to the disconnect. So far does this sound okay? I am a single man shop (and through my research) I know I can't draw more than 3.4hp at 240 V three-phase . Would this still be 3.4 hp at 600 V?

Thanks for any help in advance.
Matt M.
 
You need a Canadian code guru, and I am not he. But for sure, I'd have 60A MINIMUM on that initial distribution disconnect, 100A load center 'off the lugs' with its own main breaker if I legally could do.

Not 40A. That's nought but a b****y kitchen range or clothes dryer outlet. My 1970's vintage stick welder gets a 50A alone.

Bill
Thanks Bill for your reply. My first disconnect is going to be a 60 amp 240 single phase. I'm going to downgrade that to 40 amp using fuses as I have 60 some odd feet of 3-#8 AWG and my old stove breaker (when I switched it over to natural gas) which are both free. The welder does have a possibility of drawing up to a maximum of 59 A. The guy I bought it off of must've never exceeded 30 A as he only has a #8 AWG with a 30 amp plug.The welder is a ESAB DTA 200 square wave TIG/ARC. If I blow the fuses I will have to invest in a 60 amp breaker with #6 AWG line, which I was trying to avoid but I am prepared. My garage already is outfitted with 2 15 amp lines and split to one 15 amp 240 outlet.
 
Thanks Bill for your reply. My first disconnect is going to be a 60 amp 240 single phase. I'm going to downgrade that to 40 amp using fuses as I have 60 some odd feet of 3-#8 AWG and my old stove breaker (when I switched it over to natural gas) which are both free. The welder does have a possibility of drawing up to a maximum of 59 A. The guy I bought it off of must've never exceeded 30 A as he only has a #8 AWG with a 30 amp plug.The welder is a ESAB DTA 200 square wave TIG/ARC. If I blow the fuses I will have to invest in a 60 amp breaker with #6 AWG line, which I was trying to avoid but I am prepared. My garage already is outfitted with 2 15 amp lines and split to one 15 amp 240 outlet.

Check CAREFULLY with a welder-only branch circuit.... you may be able to install up-rated breakers, since you can with US NEC.... The wire does not always have to correspond with the breaker, since many welders are duty cycle limited, and are generally not 100% on when hand welding. The reduction is related to duty cycle by a table.
 
Check CAREFULLY with a welder-only branch circuit.... you may be able to install up-rated breakers, since you can with US NEC.... The wire does not always have to correspond with the breaker, since many welders are duty cycle limited, and are generally not 100% on when hand welding. The reduction is related to duty cycle by a table.

Well this is what's written on the back panel.
image.jpg
 
The American NEC is copyrighted. Here's a brief clip of the relevant section on wire sizing for individual welders (if the effective ampacity is not specified on the welder rating plate):

the ampacity of the supply conductors shall not be less than the current value determined by multiplying the rated primary current in amperes given on the welder rating plate by the factor shown in Table 630.11(A) based on the duty cycle of the welder.


Your welder shows 29 amps at 100% duty cycle, and 59 amps at 35% duty cucle. Table 630.11(A) has a factor of .63 for a 40% duty factor welder(factor goes in 10s), so the required ampacity of the conductors FOR THIS WELDER would 59A*.63= 37.17 amps.

In the US, you could refer your drawing and calculations to the AHJ (Authority Having Jurisdiction) for approval before installation.
 
Your welder shows 29 amps at 100% duty cycle, and 59 amps at 35% duty cucle. Table 630.11(A) has a factor of .63 for a 40% duty factor welder(factor goes in 10s), so the required ampacity of the conductors FOR THIS WELDER would 59A*.63= 37.17 amps.
Thanks wheels17 for your reply. Basically I figured for now most of my machinery needs would be under 40 A. But here is the last question I have, if I have 16 FLA at 240 V 3 phase am I safe to assume that I only have a maximum of 6 FLA when transformed to 600 V? I am trying to size fuses.
 
Matt,

I have a 15 HP RPC that I recently connected to a 240:600v transformer to power a 575v 5 HP three phase motor and I had a the local motor shop owner drop by to check out the motor and control switches and he advised the electrician as to the fuses reqr.

Awful handy to have the 600v bus now.

The 15 HP RPC is fed on a 100A breaker and delivers 60A three phase.

It cost a few dollars to connect all this but I purchased most of the disconnects and cabling used and just paid the electrician to wire it up.

Good luck with the install.

Erik

Working in New Brunswick but weekends on Prince Edward Island
 
Eric, and any others who which to reply,

I got my RPC up and running. When running my bandsaw which is a 1 1/2 hp it balances out almost perfect.

Just idling the voltage across the legs is 235, 275, 275.

When
applied draw from the bandsaw which is a 1 1/2 hp I get 235, 240, 240.
But, when I'm running other machinery with 1 hp draw I am getting 235,248,249

Now these voltages might seem pretty clean but, after being transformed from 240:600V I am getting 598, 625, 625. From the 1 hp motor

Now I would like to pull the wild leg down a tad and I was wondering what would be the easiest way about doing this.? I do have on hand a few run capacitors which I was thinking could clean up the third leg a little more. But I'm unaware of the microfarad size which would be the best fit. I as well have another motor which I could add as a secondary idler. But honestly for my power needs I don't need (in my opinion) to a second idler and would prefer to be able to just add another run capacitor. I guess sizing is more my concern.

Any help would be greatly appreciated.
 
Matt,

I am no authority here but I believe that the additional load on the RPC will improve the voltage on the wild leg as the idler runs more efficiently under load. The addition of run caps goes beyond my very limited knowledge but there are plenty of folks here who can likely help. In order to tune your RPC you need to know what load it will be running, and if the load varies it becomes more difficult.

Good luck.

Erik

Working in New Brunswick but weekends on Prince Edward Island
 
Matt,

I am no authority here but I believe that the additional load on the RPC will improve the voltage on the wild leg as the idler runs more efficiently under load. The addition of run caps goes beyond my very limited knowledge but there are plenty of folks here who can likely help. In order to tune your RPC you need to know what load it will be running, and if the load varies it becomes more difficult.

Good luck.

Erik

Working in New Brunswick but weekends on Prince Edward Island
This originally was above my train of thought. Thank you Eric, after making your post I decided to put more load adding both the bandsaw and the milling machine, and you were/are 100% correct. (With a auto service grinder deal almost hammered out, I would like to get the voltage thing cleaned up). At a 2.5 (600V) horsepower load the RPC balanced out within my ideal specs. I originally started out with a 100 µF (black to blue) and a 50 µF (red to blue) caps. Now, To keep it balanced for 1 1/2 hp or under, I needed 75 µF, 25 µF pectively. Now when I am running two machines, or more..., I'm implementing a pushbutton start to add 25 µF per leg stepping as required. I have not yet completed the tests, but so far some of the trials have been favourable. My main problem is that for each volt at 240 (estimated) and then stepped up 2.5 times (600 V) causes overvoltage which I would wish to control.
 
Matt,

I am glad that things are working out OK for you with the RPC. I know that my ideal installation would have a digital readout of current and amperage on each leg coming out of the RPC and out of the transformer for the 600v bus. Not there yet (lol). Tuning my RPC will be a treat as it has quite a few caps and it will take a while to sort out when I eventually get to it.

Erik

Working in New Brunswick but weekends on Prince Edward Island
 
Matt,

I am glad that things are working out OK for you with the RPC. I know that my ideal installation would have a digital readout of current and amperage on each leg coming out of the RPC and out of the transformer for the 600v bus. Not there yet (lol). Tuning my RPC will be a treat as it has quite a few caps and it will take a while to sort out when I eventually get to it.

Erik

Working in New Brunswick but weekends on Prince Edward Island
Eric,
I finally figured out my electrical. I guess sometimes it takes a little bit of back channeling. Originally my 600 V was too high for my liking. My Bridgeport wants only 550 V and my bandsaw 575 V. I came up with a happy medium with one running and both running. I hit my start caps dead on but my run caps needed a little tweaking. Here are my voltages not bumped up to 600vimage.jpgif you need v/a readouts let me know.
 
Matt,

That is a nice panel that you have there, I don't have continuous readout but it would certainly be handy to tweak the system.

I have my system running OK at 230v and 575v, and the next hurdle will be to get the 10 HP planer up and running at 575v in the new year.


Erik

Working in New Brunswick but weekends on Prince Edward Island
 








 
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