国外论坛上的讨论例子（转一篇英文的） 点击：818 | 回复：3
发表于：2003-05-16 09:10:00
楼主
Short circuit protection in VSD
May 12, 2003 10:48 am, by K C Oh
Subject : Motion Control
from the Automation List dept.
Text :
i,
I have a 132kw vector controlled VSD which was damaged when the motor it was driving at half load had a phase to phase short. Motor was burnt. I checked the specification of the inverter it has 4 times overcurrent protection.
Assuming all settings in the inverter is done correctly. It should have protected the VSD and motor from damages. But 2 out of 6 pieces of IGBT blown and 4 out of 6 fuses had blown.
My questions
1. VSD has overcurrent protection, does it include phase to phase short?
2. what about phase to earth short?
3. is this a VSD failure to protect the motor and itself?
Reply
--------------------------------------------------------------------------------
RE: Short circuit protection in VSD
May 12, 2003 2:44 pm, by Meir Saggie
Not really an answer - just an age old observation: The most expensive component will protect the fuse and burn out before it or
together with it. (Murphy law MLXXXIV)
Sorry to be sarcastic :-)
Meir Saggie
Reply
发表于：2003-05-16 09:08:00
1楼
RE: Short circuit protection in VSD
May 12, 2003 3:23 pm, by Anthony Kerstens
Overcurrent protection is not the same thing as short-circuit protection. I suggest you read your drive manual, or call your sales rep.
Reply
RE: Short circuit protection in VSD
May 13, 2003 3:22 pm, by k c oh
hi,
I went through the manual, it states that a overcurrent protection trip limit is 4*I(rated) instantaneously.
The manual has printed possible causes for overcurrent:
1. sudden load increase
2. short circuit in motor cables
3. unsuitable motor
In a short circuit, it is basically an instantaneous inrush current. I thought it should be covered in the overcurrent protection?
Questions:
1. Does protections means reducing damages to a minimum? Or immune from such a disaster?
2. According to their sales rep, when in such a situation, the warranty claim is void as the cause is external, ironically it seems the VSD was unable to protect itself.
What are your comments?
Reply
发表于：2003-05-16 09:09:00
2楼
RE: Short circuit protection in VSD
May 12, 2003 4:34 pm, by Donald Pittendrigh
Hi All
I suspect the overcurrent protection is designed to protect the load and not the VSD or motor. I am not a drive specialist however as I recall it
there should be and I sq Dt setting in the VSD to protect the motor and there should be some form of earth leakage detection done by the drive, I know this is the case with Siemens Masterdrives and have seen cases of all 3 of the above protections doing their job.
Perhaps the VSD was not correctly commissioned??
Donald P
Reply
发表于：2003-05-16 09:10:00
3楼
RE: Short circuit protection in VSD
May 13, 2003 9:30 am, by Alan Garwood
Ordinary fuses never blow fast enough to protect solid state power control devices against short circuit currents. I found this out after a heater destroyed an expensive SCR proportional controller. The solution is to use high speed solid state fuses.
Reply
热门招聘
相关主题
- lenze gdc 软件下载
[9603] - 变频恒压供水的基本知识[13931]
- AUT-DRIVE DV1000这个是什么...[6271]
- 今天搞维修遇到了一点问题！J...[9088]
- VFD-M台达变频器通信（三菱FX...[5732]
- 巴西、墨西哥工业电压和频率？...[14319]
- 安川G7运行显示OH1[5630]
- 智能PID控制简介 [15460]
- 变频电机的恒转矩运行和恒功...[12415]
- ABB低压电器各种问题有问必答...[15436]
官方公众号
智造工程师
-
客服
-
小程序
-
公众号
工控网智造工程师好文精选
