ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Photocell
by Docholiday. 01/22/18 10:52 AM
AreMetal Ladders Ever OK For Electrical Work?
by gfretwell. 01/22/18 01:15 AM
VDE 0100 to introduce AFCIs
by sparky. 01/20/18 05:09 PM
MRI LED lights dimmer control replacement - wow!
by Potseal. 01/19/18 08:52 PM
New in the Gallery:
Housebilding DIY wiring
SE cable question
Who's Online Now
0 registered members (), 20 guests, and 10 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
WRM controllers #128388
02/20/03 08:21 PM
02/20/03 08:21 PM
W
wocolt  Offline OP
Member
Joined: Dec 2002
Posts: 110
Scott35:
I was looking at your drawings on WRM but did not see any control for these drawings.
Are they supposed to drum-type controllers ? or run from the ground via push-buttons ?
I worked on a lot of AC cranes with this type of set-up but I never seen one with a DB for this type of application. Especially with overhauling loads and large gear-boxes.
A lot of them use Regenerative braking and if that failed the operators would reverse the controller in an emergency situation.

WOC

Tools for Electricians:
Re: WRM controllers #128389
02/23/03 02:07 AM
02/23/03 02:07 AM
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,708
Anaheim, CA. USA
WOC,

I can't remember where that schematic came from, but it was a very basic item!!!

If you could pass some more in-depth stuff my way, I would really appreciate it!!!

Scott35 S.E.T.


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
Re: WRM controllers #128390
02/23/03 08:28 AM
02/23/03 08:28 AM
G
Gwz  Offline
Member
Joined: Apr 2002
Posts: 197
This appears to be the same type I once ( and only once ) worked on in the late 60's.

The overhead crane was operated by a pendant control.

As I remmember, under heavy loads, the the actual down button was a 'low step control ' up.

If I remmember correctly the system was called "MagnaFloat"

Re: WRM controllers #128391
02/23/03 10:54 AM
02/23/03 10:54 AM
W
wocolt  Offline OP
Member
Joined: Dec 2002
Posts: 110
Scott
What are you looking for I have some older drawing of the controllers., with DB and plugging control and frequency acceleration relays.
The older models were really neat as compared to how it is done today.
One manufacture was the Paulings and Harnishfeger and there cranes were all Wound rotor motors with huge gear boxes with mechanical brakes with clutches on them to allow slip and plug stopping and reversing.
The scary thing is when the load is rated more than the crane, the operator has the hoist going up but the load is still coming down and generally they would burn up the resistances of the hoist motor. But the motor was usually fine.

WOC


Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
electure
electure
Fullerton, CA USA
Posts: 4,264
Joined: December 2000
Show All Member Profiles 
Top Posters(30 Days)
Admin 21
sparky 15
Potseal 15
Popular Topics(Views)
243,595 Are you busy
180,392 Re: Forum
170,861 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.023s Queries: 14 (0.005s) Memory: 0.9581 MB (Peak: 1.0904 MB) Zlib enabled. Server Time: 2018-01-22 16:26:54 UTC