Phase error - Electrician Talk - Professional Electrical Contractors Forum
CLICK HERE AND JOIN OUR COMMUNITY TODAY, IT'S FREE!
Go Back   Electrician Talk - Professional Electrical Contractors Forum > Electrical Trade Topics > PLCs, VFDs, Motors and Controls


Like Tree2Likes
  • 1 Post By CdotJdot
  • 1 Post By JRaef
Reply
 
Thread Tools Display Modes
Old 01-18-2016, 10:01 AM   #1
Junior Member
 
Join Date: Nov 2011
Location: Northern MN
Posts: 22
Rewards Points: 24
Default Phase error

Good morning folks I am a maintenance electrician at an injection molding facility and we just installed a brand new injection molding press that use 750 volt dc servo motors to drive the hydraulic pumps these motors are controlled by B&R drives. The new machine has auxiliary 480 volt receptacles built in to run our mold temp controllers which are basically water pumps with heating elements and dump valves to control the water temp being pumped through the molds. Now on these temp controllers there is a phase monitoring system to insure the correct rotation of the motor and when we have them connected to the machines auxiliary outlets and the servo pumps are running we will get a phase error on the temp controller but if we plug the controllers into a power source not connected to the press everything is fine and dandy. Has anybody seen somthing like this before, or could anyone explain to me their theory, any feedback would be great thank you
CdotJdot is offline   Reply With Quote
Join Contractor Talk

Join the #1 Electrician Forum Today - It's Totally Free!

ElectricianTalk.com - Are you a Professional Electrical Contractor? If so we invite you to join our community and see what it has to offer. Our site is specifically designed for you and it's the leading place for electricians to meet online. No homeowners asking DIY questions. Just fellow tradesmen who enjoy talking about their business, their trade, and anything else that comes up. No matter what your specialty is you'll find that ElectricianTalk.com is a great community to join. Best of all it's totally free!

Join ElectricianTalk.com - Click Here JOIN FOR FREE


Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. ElectricianTalk.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task!

Sponsored Links
Advertisement
 
Old 01-18-2016, 10:07 AM   #2
Junior Member
 
Join Date: Nov 2011
Location: Northern MN
Posts: 22
Rewards Points: 24
Default

Forgot to add I've tried switching leads and still get phase error and all voltage readings and connections and rotations are good
CdotJdot is offline   Reply With Quote
Old 01-18-2016, 10:39 AM   #3
Senior Member
 
backstay's Avatar
 
Join Date: Feb 2011
Location: mn
Posts: 12,376
Rewards Points: 296
Default

I there noise from the drives backfeeding the 480? Maybe the controllers are seeing that.
backstay is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-18-2016, 10:50 AM   #4
Junior Member
 
Join Date: Nov 2011
Location: Northern MN
Posts: 22
Rewards Points: 24
Default

That's all I could think of is there any way to eliminate that if that's the case
CdotJdot is offline   Reply With Quote
Old 01-18-2016, 10:54 AM   #5
Senior Member
 
backstay's Avatar
 
Join Date: Feb 2011
Location: mn
Posts: 12,376
Rewards Points: 296
Default

Quote:
Originally Posted by CdotJdot View Post
That's all I could think of is there any way to eliminate that if that's the case
Some type of filters or isolation trany. I'd put a scope on the controllers both ways to see if there is noise.
backstay is offline   Reply With Quote
Old 01-18-2016, 12:08 PM   #6
Moderator
 
John Valdes's Avatar
 
Join Date: May 2007
Location: South Carolina
Posts: 15,619
Rewards Points: 2,842
Default

Each servo motor should have an encoder or resolver attached to its shaft.
This is how the machine knows which direction these servo motors are turning.
Is it possible the encode signal is backwards? Reversed?
I mean this could be a polarity issue with one or more servo feedback devices?

I'm not exactly sure about your question. But can assure you a feedback device tells the drive in what direction the motors turn.
You may have to swap the feedback wires?
John Valdes is offline   Reply With Quote
Old 01-18-2016, 12:20 PM   #7
Junior Member
 
Join Date: Nov 2011
Location: Northern MN
Posts: 22
Rewards Points: 24
Default

Thank you for your reply John but I am not having trouble with the servo motors themselves I'm having trouble with the mold temp controllers which have a regular 480 volt 3 phase motor controlled by just a motor contactor, but when these mold temp controllers are plugged into the 480 volt auxiliary equipmemt receptacles on the press I get intermittent phase errors
John Valdes likes this.
CdotJdot is offline   Reply With Quote
Old 01-18-2016, 12:21 PM   #8
Junior Member
 
Join Date: Nov 2011
Location: Northern MN
Posts: 22
Rewards Points: 24
Default

On the controllers
CdotJdot is offline   Reply With Quote
Old 01-18-2016, 12:43 PM   #9
Moderator
 
John Valdes's Avatar
 
Join Date: May 2007
Location: South Carolina
Posts: 15,619
Rewards Points: 2,842
Default

Have you verified the phasing is the same from both sources?
John Valdes is offline   Reply With Quote
Old 01-18-2016, 12:44 PM   #10
Coffee drinking member
 
Wirenuting's Avatar
 
Join Date: Sep 2010
Location: Ceti Alpha V
Posts: 11,959
Rewards Points: 5,504
Default

Did you check input rotation with a meter?
__________________
Teacher, my brain is full... Can I go home now?
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Wirenuting is offline   Reply With Quote
Old 01-18-2016, 02:25 PM   #11
Senior Member
 
JRaef's Avatar
 
Join Date: Mar 2009
Location: SF Bay Area, California
Posts: 5,108
Rewards Points: 2,100
Default

Is this by chance a machine made overseas, and the 480V 60Hz aux power to the outlets on the machine is being created by an inverter because the machine was really designed for 380V 50Hz?

Because if so, that might explain why your external devices are indicating a phase error. They are looking for a standard sine wave power input, and you are giving them a PWM pseudo-sine wave from the inverter. When you connect them to your other "real" sources, they are seeing what they were designed to look for.
John Valdes likes this.
__________________
"If you don't know where you're going, then any direction will do." -- Lewis Carroll
JRaef is online now   Reply With Quote
The Following 2 Users Say Thank You to JRaef For This Useful Post:
cdnelectrician (01-21-2016), CdotJdot (01-22-2016)
Old 01-18-2016, 05:46 PM   #12
Registered Member
 
Join Date: Feb 2008
Location: Alabama
Posts: 11,885
Rewards Points: 1,360
Default

Be sure you're getting all three phases at the 480 receptacles.
RePhase277 is offline   Reply With Quote
Old 01-21-2016, 06:31 PM   #13
Member
 
Join Date: Apr 2014
Location: Canada,ON
Posts: 51
Rewards Points: 30
Default

Is the phase monitoring relay phasing incorrect? This would throw an error if everything else is ok... Or you could have a bad connection to the motor or the relay i'd check all these. Also id check all the fusing it could be as simple as bad fuse.

Sent from my LG-D852 using Tapatalk
Chrismcd is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
PV Inverter - Voltage Rise on One Phase NJWVUGrad General Electrical Discussion 2 01-16-2016 04:15 PM
3 Phase Converter meirmeir General Electrical Discussion 12 01-05-2016 10:04 AM


All times are GMT -4. The time now is 05:20 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.1
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Our Pro Sites Network
ContractorTalk.com | DrywallTalk.com | HVACSite.com | PaintTalk.com | PlumbingZone.com | RoofingTalk.com