CR4® - The Engineer's Place for News and Discussion®


Previous in Forum: Photovoltaics and Inverter   Next in Forum: Busbar Protection
Close
Close
Close
6 comments
Anonymous Poster #1

Isolator Switch

11/28/2017 6:20 AM

Hello All,

Found this diagram. Q0 is an Isolator Switch, and QM1 is a fuse holder.

Question is, are these two a separate assembly? - that form a sort of a backup scheme? Or, this is just one assembly, i.e. Fused Disconnect?

Please enlighten. Thanks.

Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain, and now disconnecting ["brexit" - ugh] as Little England and Wales (not too sure about Wales bit, either). Kettle's on.
Posts: 26779
Good Answers: 703
#1

Re: Isolator Switch

11/28/2017 6:41 AM

As they have two separate tag labels it looks like they are two separate items.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Reply
Guru
Hobbies - CNC - New Member

Join Date: Jul 2013
Location: Lost Wages Nevada
Posts: 1515
Good Answers: 51
#2

Re: Isolator Switch

11/28/2017 10:18 AM

Those are two separate items. Actually there isn't that much info on the diagram so it's kind of useless unless you have the other diagrams!

__________________
Though it does seem he frequently has a Swiss Army knife or Leatherman and a roll of duct tape with him.
Reply
Power-User

Join Date: Sep 2016
Location: SPAIN
Posts: 181
Good Answers: 8
#3

Re: Isolator Switch

11/29/2017 1:23 AM

The answer is: you cannot know with that amount of information. You may get two different electrical elements, with different designators, in the same assembly.

For more helpful responses a mechanical drawing will certainly be required.

__________________
Building the future!
Reply Score 1 for Good Answer
Guru

Join Date: Jul 2006
Location: CA (Central Arkansas, USA)
Posts: 548
Good Answers: 9
#5
In reply to #3

Re: Isolator Switch

11/30/2017 12:52 PM

I gave GA because all the other answers are speculation. To be sure one can (1) look at the machine (2) Get a parts breakdown (3) call mfg and ask.

Often when you try to order what looks like one part, they tell you it is only available as an assemble, or you try to order the assembly and they tell you it is only available as separate parts. Sometimes you order the assemble and get a box of separate parts. -- JHF

__________________
If it's too good to be true, it probably isn't
Reply
Guru
Engineering Fields - Instrumentation Engineering - EE from the the Wilds of Pa.

Join Date: Feb 2006
Location: middle of nowhere, Pennsylvania
Posts: 2509
Good Answers: 59
#4

Re: Isolator Switch

11/29/2017 10:14 AM

I have seen this represent a single fused disconnect and two separate items. I am guilty of this as I use cut and paste for new drawing sets and leave things as is. I use the BOM, and panel backplane layout to define if these devices are a singular item or two items. So far, in 25 years, no customer has complained. Find the bill of materials, or a component layout for your answer.

__________________
Remember when reading my post: (-1)^½ m (2)^½
Reply Score 1 for Good Answer
Guru
Engineering Fields - Power Engineering - New Member

Join Date: May 2007
Location: NYC metropolitan area.
Posts: 3005
Good Answers: 421
#6

Re: Isolator Switch

12/02/2017 8:04 PM

This particular drawing is fraught with danger. "Usually" if there is any mechanical linkage between two devices, there would be a dashed line between them indicating the operation one causes the simultaneous operation of the other. The other scenario would be that the naming convention would somehow indicate that the two are interlinked.

In this drawing it would appear that the two actions are independent of each other. If so, then the opening of QM1 would result in the voltage sensing lights going dark, erroneously indicating that the circuit was dead, regardless of the position of Q0...

Copy somebody else's work, without thoroughly understanding it, at your own risk.

__________________
Curious minds want to know, engineering minds get answers....
Reply
Reply to Forum Thread 6 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Circuit Breaker (1); Ivanov327950 (1); Original_Macgyver (1); Phys (1); PWSlack (1); RAMConsult (1)

Previous in Forum: Photovoltaics and Inverter   Next in Forum: Busbar Protection

Advertisement