# How to minimize voltage drop caused by heavy machine?

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• posted on January 30, 2015, 11:34 am

On 30/01/2015 16:05, snipped-for-privacy@spamblocked.com wrote:

Consider it uses 220V here, maybe 32 A is equivalent to 64A in the US.
I have 30 lights each rated at 85 w. That is 2550 W. I have a 2000 w saw. I have three air coolers, each 250 w. I have two computers and two laptops. I have two water dispensers. That's it for now. And most of the time, no more than 5 lights are on. The total wattage should be less than 7,000 W if everything is on.
Power company installs a meter in the landlord's office. The landlord installed a submeter in the building I rent so he knows how much electricity we use and charges us accordingly. At that time, I had a choice of installing a single phase meter of 10,000 W, the maximum capacity, or a 3 phase meter which has higher capacity. Since the service is single phase, it doesn't make sense to install a 3 phase meter and according to my calculation, I'll use no more than 7000 W. A meter of 10,000 W is enough. That's why I went for a single phase meter.

I plan to replace the switch and wires first. It can be done in one hour but I'll have to wait till after work so not to interrupt other people's work.

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<%-name%>
• posted on January 30, 2015, 2:08 pm
On Friday, January 30, 2015 at 4:39:07 AM UTC-5, snipped-for-privacy@spamblocked.com wrote:

Agree, that's pretty amazing. But I guess the total load must be under that, as I don't hear anything about the main breaker tripping. Also agree with the comments about 32A.

I'd start with an analysis of what all the loads are now, what they may be in the future.

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<%-name%>
• posted on January 30, 2015, 2:27 pm
On Thursday, January 29, 2015 at 11:38:28 PM UTC-5, yyy378 wrote:

(There is a total of 4 wires, two for hot, two for

4 mm2 is between 11 and 12 gauge. 12g would be rated for 20A. They have them doubled up, so there's your 40A capacity and the breaker is only 32A. In the US, you wouldn't be allowed to use doubled conductors like that. But from the physics, it's capable of carrying the current, within the breaker protection limit, etc. Assuming it's normal copper wire that is. If it's some cheap crap from God knows where, then who knows what it's resistance is. The fact that the switch is hot suggests something is wrong with it, possibly it's going bad. That could certainly cause your measured 5V drop. Try measuring the voltage drop across the switch.

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<%-name%>
• posted on January 30, 2015, 2:54 pm

I checked this site - http://www.rapidtables.com/calc/wire/swg-to-mm.htm - and it says a 4 mm2 wire is between #13 and #14 gauge which is quite small.
I'll just replace the switch with one of bigger capacity.

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<%-name%>
• posted on January 30, 2015, 3:53 pm
On Friday, January 30, 2015 at 9:54:51 AM UTC-5, yyy378 wrote:

I looked at several online tables, and they all say 4 mm2 is between 10 and 12 gauge.
http://xtronic.org/wp-content/uploads/2010/05/copper-awg-metric-table.jpg I'll just replace the switch with one of bigger capacity.

http://www.my-car-computer.com/image-files/wire-gauge-conversion-table.gif
http://www.tnt-audio.com/clinica/awg_e.html

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<%-name%>
• posted on January 30, 2015, 10:18 pm

Not sure what's wrong with the site I checked. It is good that 4 mm2 is between 10 and 12 gauge.

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<%-name%>
• posted on January 30, 2015, 4:18 am

Sorry. I meant to say 0.7 cm.
Hard to tell the size of the main breaker. The amp of breakers in the US are clearly marked. On the switch it tells you 15A, 20A, etc. Here, I can't find such thing. When compare different breakers, I see C10, C16, C20, C32. I guess these numbers have to be amperage rating. If that's the case, the main breaker is 32 amp.

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<%-name%>
• posted on January 30, 2015, 10:33 am
wrote:

Maybe someone else on here knows more about foreign breaker ratings, but it sounds like you're probably correct. C10 = 10 (US) C16 = 15 C20 = 20 C32 = 30
Roughly!!!
I guess a C16 (for example) gives just a tad bit more amperage, than a (US) 15A. But that makes me wonder if you'd still use #14 gauge wire? I really dont know????
I've done lots of wiring, in the US, but I'd be confused in other countries. But I normally just use #12 gauge on everything regardless if the breaker is a 15A or 20A. For the samll amount of difference in cost, I dont have to stock two different cable sizes.` I normally use 20A breakers on all outlets, and only use 15A on lighting, or a dedicated circuit for something like a furnace or sump pump.
I just googled "C32 circuit breaker". Yes, that is a common rating, lots of websites are selling them. It looks like the letter "C" has something to do with the tripping delay too. (they also have "A" "B" "D" and "E.).
--

I'm curious. Does it say the manufacturer on those breakers you have?
I doubt it's any of the common ones like Square D, GE, Siemens, etc...

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<%-name%>
• posted on January 30, 2015, 11:54 am
On 30/01/2015 17:03, snipped-for-privacy@spamblocked.com wrote:

The two most commonly used wires here are 2.5 and 4 mm. Before, I thought the unit is in millimeter but now I think it is mm2 because a wire of 4mm in diameter is close to #8 gauge. The 4mm wires I see here are not that big. I just googled 2.5 mm wire. There are many hits.j
So a 4mm2 wire is slightly smaller than #13 gauge.

I have worked with both #12 and #14 wires. #12 is stiffer, somewhat more difficult to work with.

I see ABB on the breaker. It probably is a brand name.

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<%-name%>
• posted on January 30, 2015, 1:34 pm
Would it be possible to do a soft start box for the saw?

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<%-name%>
• posted on January 30, 2015, 2:35 pm
On 30/01/2015 20:04, TimR wrote:

I was looking for something like that when I first posted but now I think I had better fix the electric system first.

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<%-name%>
• posted on January 30, 2015, 2:32 pm
On Friday, January 30, 2015 at 6:55:13 AM UTC-5, yyy378 wrote:

Where did you see that? The wire gauge tables I looked at put 4 mm2 between 10 and 12 gauge. And he says they doubled the conductors up. The breaker is 32A, so, from what I see, he has sufficient ampacity in those, ie about 50A capacity.

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<%-name%>
• posted on January 28, 2015, 11:13 pm
On 1/28/2015 4:44 PM, snipped-for-privacy@spamblocked.com wrote:

Due to the miracle of Chinese slave labor, \$30 down to \$17 on sale. http://www.harborfreight.com/clamp-on-digital-multimeter-95683.html

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<%-name%>
• posted on January 29, 2015, 3:25 am
On 29/01/2015 04:14, snipped-for-privacy@spamblocked.com wrote:

OK. I opened the panel and checked the size of the incoming wire. I can't believe what I saw. The wire, including the sheath, is only 0.7 mm. I touched the wire. It's lukewarm. The saw has been working on and off for about an hour. I'll see how much it would cost to replace the wire with a bigger one.

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<%-name%>
• posted on January 29, 2015, 2:18 am
wrote:

My simple solution would be to put the scanner on it's own dedicated UPS and unplug that UPS just before starting to use the scanner. If the existing UPS is large enough to handle the scanner and computer system for a while, you could leave the computer plugged in to it too.