What's new

Strange electrical question

mac

Well-known member
Joined
Sep 3, 2007
Messages
3,558
Reaction score
791
Points
113
I have a wash that doesn't have three phase power, instead it has a phase converter to supply the automatic. This has worked for four other automatics in the past. My issue with it is the wildly different electrical readings on the three phase motors. There is 240 single phase going into the converter. I get quite different readings coming out. As a result when I read the amp draw on the 10 hp blower motors, I get 14 amps on one leg, around 24 on another, and around 35 on the last one. This is the same on all three motors. Anyone know of a way to get these more balanced out? The tech people for the converter say to install a buck and boost transformer before the converter. The data plate on the motors say it should only draw around 22 amps at full load current. Any ideas on how to get these more inline?
 

mac

Well-known member
Joined
Sep 3, 2007
Messages
3,558
Reaction score
791
Points
113
It’s like 30K to get it pulled in and around 2K for a transformer.
 

tdlconceptsllc

Well-known member
Joined
Jul 30, 2013
Messages
1,060
Reaction score
427
Points
83
Location
NC
We assumed mac you used this into the negotiation price on buying this wash right lol I would spend the money to get it right 3 phase power bill would be alot cheaper less amps. I would think if you dont you will always be fighting this battle. If its not a carwash in the middle of the country that can only get single phase power thats a different story and understanding.
 
Last edited:

I.B. Washincars

Car Washer Emeritus
Joined
Aug 30, 2007
Messages
4,284
Reaction score
1,163
Points
113
Location
SW Indiana melon fields.
We assumed mac you used this into the negotiation price on buying this wash right lol I would spend the money to get it right 3 phase power bill would be alot cheaper less amps
Wouldn't you then have to change electrical panels inside the building? New motors? New contactors?

I'm no electrician, but I did watch one fix a lamp at the Holiday Inn Express last night. It seems like bringing in 3 phase will have a pretty significant ripple effect.
 

mac

Well-known member
Joined
Sep 3, 2007
Messages
3,558
Reaction score
791
Points
113
It was a real piece of work. Had maybe 5 owners in past 15 years. This is the fifth auto at the place and all the others used this system. Maybe I’m just getting picky. And yes I got a good deal on it. Great location in booming part of city right in main business district. Starbucks next door(which I really don’t care for but good clients). Getting this close to having the auto done. Then all the other stuff to make it a showplace. Will post pictures when I catch my breath and I can figure out how to do that. Wife brought up the best part. This is the last auto I will ever do, so want to make it perfect. Any others I’ll hire it all out, sit in a lawn chair with a cocktail and just offer suggestions. And this machine kicks butt. Only one in entire state that does tall vans. Life is good.
 

mjwalsh

6 bay SS w/laundromat
Joined
Sep 7, 2007
Messages
3,134
Reaction score
173
Points
63
Location
North Dakota
If it is that expensive ($30K) just to get the utility company to bring in 3 phase to the building & no further, I would say to use VFDs & inverter duty motors like some of our laundromat equipment. Just a thought.
 

mac

Well-known member
Joined
Sep 3, 2007
Messages
3,558
Reaction score
791
Points
113
MJ, for a laundromat I am guessing the biggest motors you have are one hp or less. The blowers here have a total of 30 hp. Because of my location in a busy area, the 3 phase power is maxed out. So for me to get it I have to pay for them to upgrade the entire block. That is just to bring it to my building. I would then need a licensed sparky to replace entire panel and then for me to do equipment upgrades. It adds up quickly. Maybe I should just go solar and be a green business.
 

JGinther

Zip-tie engineer
Joined
May 31, 2008
Messages
743
Reaction score
170
Points
43
Location
Loveland, CO
What is the FLA on the blower motors? If they are spinning at full speed and not exceeding by 10% on any leg, I don't think i would do anything. I'm assuming you have proper overcurrent and overload protection on the motor... I would be more concerned about the phase generator holding up and would probably do what they recommend. Are you using a True RMS meter?
 

GoBuckeyes

Self-Serve and Automatics
Joined
Aug 30, 2007
Messages
1,076
Reaction score
347
Points
83
Location
Cleveland
Is the jury rigged three phase power the reason they have gone through 5 Autos in the last 15 years?
 

Dan kamsickas

GinSan Technician
Joined
Aug 31, 2007
Messages
705
Reaction score
941
Points
93
Location
Grand Rapids, MI
It’s like 30K to get it pulled in and around 2K for a transformer.
How long are you planning on keeping the wash? 3 phase will halve your amp draw, on average. Long term, 3ph may be the less expensive option. It all depends on how long the payback is and how long you plan on being there. Not to forget, 3ph motors have a lot longer life expectancy than single phase. Single phase motors have gotten crazy expensive and the warranties are crap. I would push back on the power company. Their grid is not your responsibility.
 

mjwalsh

6 bay SS w/laundromat
Joined
Sep 7, 2007
Messages
3,134
Reaction score
173
Points
63
Location
North Dakota
MJ, for a laundromat I am guessing the biggest motors you have are one hp or less. The blowers here have a total of 30 hp. Because of my location in a busy area, the 3 phase power is maxed out. So for me to get it I have to pay for them to upgrade the entire block. That is just to bring it to my building. I would then need a licensed sparky to replace entire panel and then for me to do equipment upgrades. It adds up quickly. Maybe I should just go solar and be a green business.
Mac,

I might be worth it to give the below outfit's tech support a call. They are specifically stating avoiding the need for a 3 phase hookup for over 30 HP motors???

 

mac

Well-known member
Joined
Sep 3, 2007
Messages
3,558
Reaction score
791
Points
113
Mac,

I might be worth it to give the below outfit's tech support a call. They are specifically stating avoiding the need for a 3 phase hookup for over 30 HP motors???

Looked at their website and don’t see them as a viable solution. Thheir smallest motor is 30hp. I have 3 tenhp motors. This is a real head scratcher. Keeps tripping overloads. Just can not understand why the previous Machines ran on this but mine doesn’t. Fri afternoon late. Time for happy hour and ruminate.
 

mac

Well-known member
Joined
Sep 3, 2007
Messages
3,558
Reaction score
791
Points
113
Don't know. Running only one of three blowers is not an option.
 

JGinther

Zip-tie engineer
Joined
May 31, 2008
Messages
743
Reaction score
170
Points
43
Location
Loveland, CO
It is. You just disconnect the 3 wires and I'm pretty sure the blower won't turn on.:p Trying to see if your results are tied to heavy loading or not. Would definitely need to watch the voltage/current and measure using a true rms meter at the same time to get any meaningful data.
 

mac

Well-known member
Joined
Sep 3, 2007
Messages
3,558
Reaction score
791
Points
113
It is. You just disconnect the 3 wires and I'm pretty sure the blower won't turn on.:p Trying to see if your results are tied to heavy loading or not. Would definitely need to watch the voltage/current and measure using a true rms meter at the same time to get any meaningful data.
Well the man upstairs must have felt sorry for me. Went in today and the darn thing. Worked. There are timers to stage the starting and all three had same readings (and yes with a true RMS meter). Can’t explain it. As i journey through life I am convinced that there are things that we are simply not meant to understand. So after almost 3 months we are finally opened! Took longer and more money than I thought (sound familiar?) but it’s done right, looks damn good, and turns out a spectacular wash. Pictures at 11.
 
Top