Planning a Electrical Run - 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 Forum > General Electrical Discussion


Like Tree10Likes
  • 1 Post By MechanicalDVR
  • 1 Post By VELOCI3
  • 4 Post By varmit
  • 1 Post By RICK BOYD
  • 1 Post By varmit
  • 1 Post By Navyguy
  • 1 Post By Navyguy
Reply
 
Thread Tools Display Modes
Old 08-18-2019, 11:38 PM   #1
Member
 
Maintenance2's Avatar
 
Join Date: Oct 2018
Location: Indiana
Posts: 64
Rewards Points: 6
Default Planning a Electrical Run

Have 4 new exhaust fans in differenent places of the building about 100 feet apart. 480vac 3phase 2hp motors on each. Pulling from a 480vac bus duct. How would do this run? Separate combo starters for each exhaust fan in a easily accessible location? Would you put anything else in the circuit?
Maintenance2 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 08-19-2019, 12:02 AM   #2
Cow
Senior Member
 
Join Date: Jan 2008
Location: Eastern Oregon
Posts: 2,926
Rewards Points: 4,688
Default

What controls the fans?
Cow is offline   Reply With Quote
Old 08-19-2019, 02:09 PM   #3
Member
 
Join Date: Aug 2019
Location: NY
Posts: 73
Rewards Points: 90
Default

Using buss disconnect transitions or buss to panel then feed the starters?
Location depends. Nice to have that type of equipment coming from one MCC but anything is possible. There are many many (police academy) options

Last edited by VELOCI3; 08-19-2019 at 02:12 PM.
VELOCI3 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 08-19-2019, 03:11 PM   #4
Old Grumpy Bastard
 
MechanicalDVR's Avatar
 
Join Date: Dec 2007
Location: "Old Dominion"
Posts: 59,588
Rewards Points: 1,588
Default

Do you have a semi central spot for a sub panel and the starters that is convenient?
bill39 likes this.
__________________
I'm as Christian as possible in the times we live in.

Always just a stallion in a china shop
MechanicalDVR is offline   Reply With Quote
Old 08-19-2019, 05:23 PM   #5
Senior Member
 
just the cowboy's Avatar
 
Join Date: Sep 2013
Location: Colorado
Posts: 1,636
Rewards Points: 18
Default

Local disconnects? I think exhaust fans need them not sure.
__________________
A cowboy may get thrown down, but he always gets up and walks forward and don't look back at what thru him.
just the cowboy is offline   Reply With Quote
Old 08-19-2019, 06:00 PM   #6
Old Grumpy Bastard
 
MechanicalDVR's Avatar
 
Join Date: Dec 2007
Location: "Old Dominion"
Posts: 59,588
Rewards Points: 1,588
Default

Quote:
Originally Posted by just the cowboy View Post
Local disconnects? I think exhaust fans need them not sure.
YES they do, with in sight.
__________________
I'm as Christian as possible in the times we live in.

Always just a stallion in a china shop
MechanicalDVR is offline   Reply With Quote
Old 08-19-2019, 06:10 PM   #7
Member
 
Join Date: Aug 2019
Location: NY
Posts: 73
Rewards Points: 90
Default

Quote:
Originally Posted by just the cowboy View Post
Local disconnects? I think exhaust fans need them not sure.


Yes. You can use a 3 pole 30A safety switch or a 3 pole 20A toggle (rated at 480V).


Sent from my iPhone using Tapatalk
Paul SA likes this.
VELOCI3 is offline   Reply With Quote
Old 08-19-2019, 08:50 PM   #8
Senior Member
 
Join Date: Apr 2009
Location: Northern Kentucky
Posts: 1,359
Rewards Points: 1,620
Default

Probably, the most cost effective method, with small motors as these, would be to assemble a panel with a local disconnect,all of the individual motor fusing, the starters, and the control devices. This would only require one circuit from the buss duct. If these fans are for general building ventilation, as in that they are not stopped and started often, you could use IEC starters to save space in the panel.

A 2 HP motor on 480 would only pull about 3.5 amps each. So four buss disconnects would be over kill.
Navyguy, glen1971, splatz and 1 others like this.
varmit is offline   Reply With Quote
Old 08-20-2019, 06:34 AM   #9
Member
 
Paul SA's Avatar
 
Join Date: Jul 2019
Location: Gauteng province Johannesburg South Africa
Posts: 77
Rewards Points: 148
Default

Quote:
Originally Posted by varmit View Post
Probably, the most cost effective method, with small motors as these, would be to assemble a panel with a local disconnect,all of the individual motor fusing, the starters, and the control devices. This would only require one circuit from the buss duct. If these fans are for general building ventilation, as in that they are not stopped and started often, you could use IEC starters to save space in the panel.

A 2 HP motor on 480 would only pull about 3.5 amps each. So four buss disconnects would be over kill.
i agree with Varmit don't over think it this small motors does not require to much design

Last edited by Paul SA; 08-20-2019 at 06:37 AM.
Paul SA is offline   Reply With Quote
Old 08-20-2019, 02:34 PM   #10
electrorick
 
RICK BOYD's Avatar
 
Join Date: Mar 2008
Location: st. Joe, Missouri
Posts: 217
Rewards Points: 221
Default

just the cowboy


that horse didn't throw me !
that's just the way I get offem !
Paul SA likes this.
__________________
I know you understand
what you thought I said
but what you heard
is not what I meant
RICK BOYD is offline   Reply With Quote
Old 08-21-2019, 10:57 AM   #11
Member
 
Maintenance2's Avatar
 
Join Date: Oct 2018
Location: Indiana
Posts: 64
Rewards Points: 6
Default

When you say local disconnect. Does that mean each motor with a within sight disconnect? Or just 1 disconnect centrally located? Theres no way to centrally locate it to be within sight of each motor. Or 4 disconnects for each individual motor centrally located? We have a open spot to centrally locate. When you say panel what kind do you mean?
Maintenance2 is offline   Reply With Quote
Old 08-21-2019, 10:30 PM   #12
Senior Member
 
Join Date: Apr 2009
Location: Northern Kentucky
Posts: 1,359
Rewards Points: 1,620
Default

Depending on your plant rules/ specs (if any exist) as long as the starter panel disconnect is lockable in the off position, this could be the lock out point for all four motors. Otherwise, a local disconnect would be required at or "within sight of" each motor.

The "panel" that I am speaking of would be a Hoffman type industrial enclosure of a type that would suit the environment - NEMA 1, NEMA 12, etc. You purchase a separate back panel, for the enclosure, to mount and assemble and wire your components. You would need : a disconnect for the panel, individual motor fusing, the starters and overloads and a small control power transformer. Your manual control devices- push buttons or selector switches, could be installed in the panel door, or be installed close to each fan position with the control wires being routed to the fan control panel.
glen1971 likes this.
varmit is offline   Reply With Quote
Old 08-21-2019, 10:56 PM   #13
Chief Flunky
 
Join Date: Oct 2017
Location: Carolinas
Posts: 996
Rewards Points: 330
Default

Quote:
Originally Posted by varmit View Post
Depending on your plant rules/ specs (if any exist) as long as the starter panel disconnect is lockable in the off position, this could be the lock out point for all four motors. Otherwise, a local disconnect would be required at or "within sight of" each motor.

The "panel" that I am speaking of would be a Hoffman type industrial enclosure of a type that would suit the environment - NEMA 1, NEMA 12, etc. You purchase a separate back panel, for the enclosure, to mount and assemble and wire your components. You would need : a disconnect for the panel, individual motor fusing, the starters and overloads and a small control power transformer. Your manual control devices- push buttons or selector switches, could be installed in the panel door, or be installed close to each fan position with the control wires being routed to the fan control panel.


Why not just use a combination starter panel? Everything is already prewired including start/stop buttons.

The “within sight of” rule has an exception for supervised installations where qualified workers work on it. No local disconnects needed.

Wiring wise depends on plant rules. Near a roof so type AC or MC is probably the cheapest and fastest. PVC a little more money and time, and IMC or rigid the slowest. If corrosion and moisture is an issue I’d stick with PVC and THWN-2.


Sent from my iPhone using Tapatalk
paulengr is offline   Reply With Quote
Old 08-22-2019, 12:04 PM   #14
Senior Member
 
Join Date: Jun 2008
Location: Colleyville, Tx
Posts: 749
Rewards Points: 928
Default

If those fans are for smoke removal, they have to be controlled from within a fire rated room
cdslotz is offline   Reply With Quote
Old 08-22-2019, 12:18 PM   #15
Senior Member
 
Join Date: Mar 2010
Location: Welland, Ontario Canada
Posts: 2,206
Rewards Points: 4,122
Default

My approach I think would be similar to @varmit explanation. I would take a single circuit from the buss to a control panel. In the panel I would have multiple starters; depending on the requirements for running (on / off, start/ stop), interlock, air flow, temperature, etc I might just put in a terminal strip and wire directly or I might use a programmable relay or even a small PLC.

This approach will determine if you are controlling at line voltage or a lower voltage. I would then put a HP rated 3 pole toggle switch at each fan for maintenance; something like a Hubbell HBL7810D which you can get a variety of lockable enclosures for depending on your environment.

The hard work is not getting the fans to run, but is how they are they controlled? This will actually have a larger impact on your design then the physical and electrical requirements of each fan.

Cheers
John
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Navyguy is offline   Reply With Quote
Old 08-22-2019, 12:44 PM   #16
Senior Member
 
Join Date: Oct 2012
Location: Alberta Rockies
Posts: 2,725
Rewards Points: 3,808
Default

Quote:
Originally Posted by Navyguy View Post
My approach I think would be similar to @varmit explanation. I would take a single circuit from the buss to a control panel. In the panel I would have multiple starters; depending on the requirements for running (on / off, start/ stop), interlock, air flow, temperature, etc I might just put in a terminal strip and wire directly or I might use a programmable relay or even a small PLC.

This approach will determine if you are controlling at line voltage or a lower voltage. I would then put a HP rated 3 pole toggle switch at each fan for maintenance; something like a Hubbell HBL7810D which you can get a variety of lockable enclosures for depending on your environment.

The hard work is not getting the fans to run, but is how they are they controlled? This will actually have a larger impact on your design then the physical and electrical requirements of each fan.

Cheers
John
Why not one starter to control all four fans so that they are all either on or all off? So there would be one feed from the bus to the starter, one feed out from that starter either to a local junction box with 4 feeds out of it and terminal jumpers from the feed to each fan's supply, or splice the wires in a fitting for each starter where ever you put in a pipe tee, or at each starter, depending on routing and layout. Then have a lockable disconnect switch at each fan for maintenance.
glen1971 is offline   Reply With Quote
Old 08-22-2019, 12:55 PM   #17
Senior Member
 
Join Date: Mar 2010
Location: Welland, Ontario Canada
Posts: 2,206
Rewards Points: 4,122
Default

Quote:
Originally Posted by glen1971 View Post
Why not one starter to control all four fans so that they are all either on or all off? So there would be one feed from the bus to the starter, one feed out from that starter either to a local junction box with 4 feeds out of it and terminal jumpers from the feed to each fan's supply, or splice the wires in a fitting for each starter where ever you put in a pipe tee, or at each starter, depending on routing and layout. Then have a lockable disconnect switch at each fan for maintenance.
Agreed if that is the way they are supposed to be controlled. I am not clear on how they are supposed to operate; as a group, semi-independently or totally independently. If they were all running as a group I might consider a simple manual switch at each fan with a heater in it for protection and not have a set of OLs in the starter.

Again it is all in how they are to be controlled.

Cheers
John
glen1971 likes this.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Navyguy is offline   Reply With Quote
Old 08-22-2019, 04:00 PM   #18
Member
 
Maintenance2's Avatar
 
Join Date: Oct 2018
Location: Indiana
Posts: 64
Rewards Points: 6
Default

There just going to be used as general building ventilation exhaust fans. There leaving how they are going to be controlled up to be. Planned on just a start and stop to control them but now considering other options. All of our older fans in other building are just on or off. Is it common to use airflow or temperature to control these fans?
Maintenance2 is offline   Reply With Quote
Old 08-22-2019, 06:05 PM   #19
Senior Member
 
Join Date: Mar 2010
Location: Welland, Ontario Canada
Posts: 2,206
Rewards Points: 4,122
Default

Quote:
Originally Posted by Maintenance2 View Post
Is it common to use airflow or temperature to control these fans?
Anything is common if it is required as part of process or environmental control. As an example as part of an ISO requirement a building may be required to have so many air changes (exchanges) in an hour. But that requirement may only apply when a specific process is in operation.

As in another thread, there maybe a requirement just to get the heat out of an area once it rises to a specific temperature. That may involve a staged approach that will start one fan at a time until the desired temperature is reached.

In poultry barns there is a combination of temperature and speed control as there is a pretty specific temperature that must be maintained and little room for deviation.

Cheers
John
glen1971 likes this.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Navyguy is offline   Reply With Quote
Old 08-22-2019, 09:36 PM   #20
Member
 
Join Date: Aug 2019
Location: NY
Posts: 73
Rewards Points: 90
Default

Quote:
Originally Posted by Navyguy View Post
Anything is common if it is required as part of process or environmental control. As an example as part of an ISO requirement a building may be required to have so many air changes (exchanges) in an hour. But that requirement may only apply when a specific process is in operation.



As in another thread, there maybe a requirement just to get the heat out of an area once it rises to a specific temperature. That may involve a staged approach that will start one fan at a time until the desired temperature is reached.



In poultry barns there is a combination of temperature and speed control as there is a pretty specific temperature that must be maintained and little room for deviation.



Cheers

John


Yup. Find out what the requirements are from the customer (if there even are any) and THEN ask for recommendations on how to implement. As you see we can do NASA to poultry barns. The trick is you have to figure out which one you are working in.


Sent from my iPad using Tapatalk
VELOCI3 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



All times are GMT -4. The time now is 04:23 AM.


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