Electrician Talk banner

1 - 20 of 25 Posts

·
Registered
Joined
·
63 Posts
Discussion Starter #1
Trying to troubleshoot a cnc mill in a machine shop. It is getting a low voltage warning. The panel is a 120/208v 3ph. The feed to the panel reads 200 volts ph to ph with less than half of the panel load running. The mill is another 40-50 feet away fed with #10 mc cable on a 3 pole 30 amp breaker. The mill fla is 30 amps at I think 240 volt 3ph. The owner thinks a buck boost transformer will boost the voltage. Where would you guys begin?
 

·
Registered
Joined
·
4,665 Posts
I'd start by finding out why the feed to the panel is so low. :whistling2:

Buck/boost is a band-aid fix and since the panel feed is on the low side with "less than half the panel load running" you have a problem somewhere in that feeder.

What is the voltage with NO load on the panel?
What is the voltage with all the normal loads running?

You need to dig deeper and find the real issue before spending buck on transformers. :thumbsup:
 

·
Registered
Joined
·
63 Posts
Discussion Starter #3
I looked back through my pics.
Here is the name plate of the mill. I also have a pic of the 1st smaller panel, and 2nd larger panel where the mill is fed from. The electrical has been pieced together poorly. The feed to the 1st panel looks to be 100 amps. I go there tomorrow morning and will check the feeder breaker from the gear. The owner did say a previous electrician said the connections looked really bad, and that was 4 years ago.
 

Attachments

·
Registered
Joined
·
12,167 Posts
Buck Boost is a good way to bring 208 up to 240 for the motor, but getting the voltage from 200 up to 208 is better served with having an adequate electrical distribution system.

What is the incoming voltage at the service disconnect? How much does the voltage drop from no load to loaded?
 

·
Registered
Joined
·
63 Posts
Discussion Starter #6
Sorry guys I was mistaken, It's rated at 220 volt. I will check the load, no load voltage at the service disconnect tomorrow, then compare with the lugs at the top of the panel.
 

·
Registered
Joined
·
2,966 Posts
Why is your so called 208 reading only 200 ?
With normal or little load it should be very close to,or higher than this figure !
Check out all connections and switch gear
And also measure your main service drop voltage
if it's already low here then it's poco's problem

.....
 

·
IBEW L.U. 1852
Joined
·
5,261 Posts
All good advice ......

For all you know......this guy could be one of the best construction electricians you have ever met and has little to no experience with troubleshooting equipment after the installation.

Check your voltages with and without load at every point you can find that feeds to the CNC mill. It could be low directly from the POCO.
 

·
evil bastard
Joined
·
15,771 Posts
Why is your so called 208 reading only 200 ?
With normal or little load it should be very close to,or higher than this figure !
Check out all connections and switch gear
And also measure your main service drop voltage
if it's already low here then it's poco's problem
...... 200 volts is still well within nema guidelines of our infrastuture and nominal voltage. .........

His problem is he's running a240 volt machine on 208
 

·
Electrical Contractor
Joined
·
9,327 Posts
Does your machine have a control xfmr? If it does, what tap is the primary and/or the secondary connected to?
See section 4.8.6
 

·
Registered
Joined
·
1,543 Posts
Which Fault Code are you getting?
Are you getting Fault Code 9?
from the owner's manual:

"Code 9 - DC link under voltage: The power drive module will report under voltage conditions. If an under voltage condition exists, the power drive module will shut down the output and report fault condition "9". The under voltage trip point is 170VDC for 230VAC power drive modules. These voltages are set in the hardware. Check the DC voltage across the terminals labeled B- and B+. At 230 volts the DC voltage should be approximately 300 VDC."

What is your DC voltage? Is it possible that the DC power supply is putting out low voltage or is failing?
 

·
Registered
Joined
·
1,543 Posts
Another possibility - According to the owner's manual, it will run on 208 volts. You have 200 volts, find out why.
Since the variable is 208 - 240, anything under 208 V may be throwing the Code.

In the owner's manual read section 3.3.6 System Will Not Turn On or Boot-Up also read section 4.8
 

·
Registered
Joined
·
1,543 Posts
Page 67:
"Note: systems running consistently close to the high or low values may have problems when normal voltage fluctuations push the voltage out of the acceptable range.
Our system is shipped out assuming the customers shop has 220 V power. The transformer secondary tap is set on 115 volts. Measure the voltage coming out of the transformer by placing the voltmeter across the 115 V and 0 V taps. If this measurement is above 120 volts then move the tap from 115 V to 110 V. If the reading is low, 110 V or below, then change the tap from 115 V to 124 V. Input power to the machine that is 230 V

WARNING!
Do not plug and unplug connectors with the system power on. This may cause damage to the connector board and harm to the technician.
TRAK DPM V3, V5 & V7 Safety, Installation, Maintenance, Service & Parts List
or above will cause the 110 voltage to be high and voltage that is 208 V or below typically causes 110 voltage to be low."
 

·
Registered
Joined
·
4,665 Posts
Ok guys, enough of the ragging in here...next person to post any more smart ass commentary is going on vacation.

If anyone has reason to question anyone's qualifications, REPORT THE POST IN QUESTION AND DO NOT POST YOUR DOUBTS ON A THREAD.

As Rollie73 pointed out, the OP may not have much experience at troubleshooting, not everyone has the "electron whisperer" genes.

Offer constructive help to the OP or keep your trap shut.
 

·
IBEW L.U. 1852
Joined
·
5,261 Posts
Ok guys, enough of the ragging in here...next person to post any more smart ass commentary is going on vacation.

If anyone has reason to question anyone's qualifications, REPORT THE POST IN QUESTION AND DO NOT POST YOUR DOUBTS ON A THREAD.

As Rollie73 pointed out, the OP may not have much experience at troubleshooting, not everyone has the "electron whisperer" genes.

Offer constructive help to the OP or keep your trap shut.
Exactly where I was going with my comment which you so graciously edited for me:laughing:.

Its completely out of hand on this forum. Practically every time a new member comes on the forum he/she is greeted with some form of arrogant remark.

Lets get the new members used to this place and make them feel comfortable and at home on the forum before we start being a$$holes to them:thumbup:
 

·
Premium Member
Joined
·
7,420 Posts
Lets get the new members used to this place and make them feel comfortable and at home on the forum before we start being a$$holes to them:thumbup:
:thumbsup::laughing: ^

I can't see 240V on the nameplate ? McClary see's it somewhere, or is he assuming it wouldn't give a low voltage indicator if it was only 208V ?
 

·
Registered
Joined
·
63 Posts
Discussion Starter #19
Wow, I appreciate all the responses, thanks guys. I will check it out tomorrow using all of your recommendations. Btw, I zoomed in on the name plate and says 220v.
 

·
Electrical Contractor
Joined
·
9,327 Posts
Ok guys, enough of the ragging in here...next person to post any more smart ass commentary is going on vacation.

If anyone has reason to question anyone's qualifications, REPORT THE POST IN QUESTION AND DO NOT POST YOUR DOUBTS ON A THREAD.

As Rollie73 pointed out, the OP may not have much experience at troubleshooting, not everyone has the "electron whisperer" genes.

Offer constructive help to the OP or keep your trap shut.
I'm sorry if I in any way, shape or form "ragged" on the OP or brought into question his intelligence. I promise to share with him my winnings from the Publishers Clearing House when UPS finally delivers it as was promised me last week. Whoops! I think I might have just posted a smart *** comment.
See ya!:laughing:
 
1 - 20 of 25 Posts
Top