VFD INSTALLATION IN OLD HOSPITAL
VFD INSTALLATION IN OLD HOSPITAL
(OP)
HELLO
I AM AN OPERATION ENGINEER IN A HOSPITAL IN BRONX NY.THE HOSPITAL IS ABOUT 40 YEARS OLD AND IT'S PRIMARY SERVICE IS 208V 3PHASE 60hz. IT IS SITUATED IN AN INDUSTRIAL AREA WITH FACTORIES AS WELL AS OTHER MEDICAL FACILITIES.ALL OF WHICH SHARE A COMMON POWER GRID WITH US.
ALL OF MY MOTOR CONTROLES AT THIS TIME ARE CONTACTOR TYPE.
IMINANT RENOVATIONS TO MUCH OF OUR MACHANICAL SPACES CALL FOR THE INSTALLATION OF SOME (16) 6 PULSE VFD'S,RANGING IN SIZE FROM 20-60 HP.
IN MY TEN YEARS HERE I HAVE SEEN THE INTRODUCTION OF ALOT OF SENSITIVE ELECTRONICS ,MOSTLY IN OUR OR WINGS.MANY OF THESE DEVICES HAVE SUFFURED PROBLEMS DUE TO POWER QUALITY(AS PER THEIR MANUFACTURERS).UPS AND OTHER TYPES OF LINE FILTERS HAVE BEEN USED TO CORRECT THESE PROBLEMS.
WHAT INFORMATION I HAVE BEEN ABLE TO FIND INDICATES THE 6 PULSE DRIVES HAVE A POTENTIAL TO ADD TO WHAT I BELIEVE TO BE AN HARMONICS PROBLEM IN THE HOSPITAL.
THE VENDERS HAVE DISMISED MY CONCERNS TO THE HIGHER UPS.AND SUBSEQUENTLY MY REQUESTS FOR AN HARMONICS STUDY PRIOR TO THE VFD INSTALLATIONS.
IF IM SPINNING MY WHEELS ABOUT NOTHING FEEL FREE TO TELL ME SO. NOT LOOKING FOR ANYONE TO DUE MY WORK FOR ME ,JUST GIVE ME A PIONT IN THE RIGHT DIRECTION. THOUGH I HAVE BEEN AN ELECTRICIAN FOR OVER 18 YEARS IM FEELING A LITTLE OVER MY HEAD ON THIS ONE.
THANKS IN ADVANCE TO ALL
I AM AN OPERATION ENGINEER IN A HOSPITAL IN BRONX NY.THE HOSPITAL IS ABOUT 40 YEARS OLD AND IT'S PRIMARY SERVICE IS 208V 3PHASE 60hz. IT IS SITUATED IN AN INDUSTRIAL AREA WITH FACTORIES AS WELL AS OTHER MEDICAL FACILITIES.ALL OF WHICH SHARE A COMMON POWER GRID WITH US.
ALL OF MY MOTOR CONTROLES AT THIS TIME ARE CONTACTOR TYPE.
IMINANT RENOVATIONS TO MUCH OF OUR MACHANICAL SPACES CALL FOR THE INSTALLATION OF SOME (16) 6 PULSE VFD'S,RANGING IN SIZE FROM 20-60 HP.
IN MY TEN YEARS HERE I HAVE SEEN THE INTRODUCTION OF ALOT OF SENSITIVE ELECTRONICS ,MOSTLY IN OUR OR WINGS.MANY OF THESE DEVICES HAVE SUFFURED PROBLEMS DUE TO POWER QUALITY(AS PER THEIR MANUFACTURERS).UPS AND OTHER TYPES OF LINE FILTERS HAVE BEEN USED TO CORRECT THESE PROBLEMS.
WHAT INFORMATION I HAVE BEEN ABLE TO FIND INDICATES THE 6 PULSE DRIVES HAVE A POTENTIAL TO ADD TO WHAT I BELIEVE TO BE AN HARMONICS PROBLEM IN THE HOSPITAL.
THE VENDERS HAVE DISMISED MY CONCERNS TO THE HIGHER UPS.AND SUBSEQUENTLY MY REQUESTS FOR AN HARMONICS STUDY PRIOR TO THE VFD INSTALLATIONS.
IF IM SPINNING MY WHEELS ABOUT NOTHING FEEL FREE TO TELL ME SO. NOT LOOKING FOR ANYONE TO DUE MY WORK FOR ME ,JUST GIVE ME A PIONT IN THE RIGHT DIRECTION. THOUGH I HAVE BEEN AN ELECTRICIAN FOR OVER 18 YEARS IM FEELING A LITTLE OVER MY HEAD ON THIS ONE.
THANKS IN ADVANCE TO ALL






RE: VFD INSTALLATION IN OLD HOSPITAL
The only way to determine if there will be a problem is to either perform a study or install the drives and do some harmonic surveying.
The first step in a study will be to request the harmonic operating signature from the drive manufacturer, anyway, so you may be able to see what the typical output would look like and get an idea how it would affect your system.
RE: VFD INSTALLATION IN OLD HOSPITAL
That said, if you have already solved ALL of your power quality problems with UPS systems and power conditioners, it may be true that the VFD harmonics effects will not get through to the places where they would have life-safety consequences. However I agree with DanDel, your "higher ups" should commission a study at the very least).
"Venditori de oleum-vipera non vigere excordis populi"
RE: VFD INSTALLATION IN OLD HOSPITAL
RE: VFD INSTALLATION IN OLD HOSPITAL
RE: VFD INSTALLATION IN OLD HOSPITAL
If the equipment being applied on the VFD's is critical in nature, your engineer should carefully evaluate those motors. Many old motors have failed quickly when connected to a new drives. New motors should be specified for VFD application. Motor lead length should be limited per the drive mfg's recommendation.