Electric Chain Hoist cabling concept

[Histor]

Hi All,

I have an Electric Chain Hoist with Cross Travel motor and Hoist Motor. Vendor mentioned both of these motors are running with DOL Starter.
They asked me to provide power supply up to isolator. Do I need to provide Supply to both the motors separately from two DOL starters? or Do I need to give 3phase 4Wire supply to them and there will be a local panel with Starters inside the hoist package? If I need to provide individual Supply from Motor control center with DOL starter, Do I need to give 2 isolators near Hoist?

I never worked on This type of hoist. Please help me based on your experience. Below is the snap from the drawing vendor send to me.

 

[RedSnake]

The electrical drawing for the Electric Chain Hoist with Cross Travel motor and Hoist Motor would have been more helpful.
It depends on how the feed distribution looks like in there cabinet from the incoming connection point.
I suggest you ask the vendor, more exactly what he needs from you.

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[che12345]

Dear Mr. Histor (Electrical)(OP)30 Dec 22 05:4
".... #1. I have an Electric Chain Hoist with Cross Travel motor and Hoist Motor. Vendor mentioned both of these motors are running with DOL Starter...."
1. Both motors are with DOL starting, fine.

"...#2. They asked me to provide power supply up to isolator. ....#3. Do I need to provide Supply to both the motors separately from two DOL starters? or Do I need to give 3phase 4Wire supply to them and there will be a local panel with Starters inside the hoist package? ....#4. If I need to provide individual Supply from Motor control center with DOL starter, Do I need to give 2 isolators near Hoist?..."
2. Although it depends on the contract specification, the usual practice on the market is what the hoist fabricator asked for " provide sufficient power (voltage and current rating) up to the isolator [ located close to the hoist at, ground level. All the other electrical works shall be covered by the hoist fabricator.
3. No. See above 2. Usually you may? supply (3-phase 3W + PE, without N) with correct voltage, current rating. Reconfirm with the hoist fabricator whether N is needed.
4. See above 2. No. Only ONE isolator for isolating the whole system for maintenance work etc....
Che Kuan Yau (Singapore)

 

[FacEngrPE]

I concur with che12345. The hoist - with two motions constitutes a single machine. It gets a single feeder with a single disconnect for the machine.

 

[Histor]

When Connecting two motors in Single starter, the contactor would not be able to provide adequate thermal protection during overload if both the motor ratings are different.

 

[che12345]

Dear Mr.Histor (Electrical)(OP)30 Dec 22 23:59
"....When Connecting two motors in Single starter, the contactor would not be able to provide adequate thermal protection during overload if both the motor ratings are different."
1. In your case for the hoist, there are two separate motors. One for hoist, the other for travel. They can be same or different kW rating , is irreverent.
2. Usually only one motor is in operation. It is also possible two of them are in operation. Controlled by different (start stop), (up down) push-buttons. There shall be two sets of reversing starters. Each reversing starter comprising of two contactors, but only one over-load rated for the motor. Therefore, there shall be Two sets of [reversing starter] In each set, shall have two contactors, but with only one thermal-overload.
Che Kuan Yau (Singapore)

 

[FacEngrPE]

Mr Che is correct for both

https://www.eng-tips.com/viewthread.cfm?qid=501113

the IEC case where he is the expert, and for the NEC case.

The described monorail hoist system is viewed as a machine, with a feeder (outside of the machine) having rules for designing the feeder. Inside the machine of the monorail hoist system is the travel system, and the hoist system each with their motors, controls, and safety systems. Usually all of the stuff that make up the inside of the machine is provided by the machine supplier.
You must use the design / construction rules (IEC, NEC, etc) that apply to your location.

 

[waross]

Check the code for cable size for the two motors.
Run a cable only to an isolator.
Check the specs.
The isolator is most likely supplied with the hoist package.
If not Install a suitable isolator (check your codes) and run a suitable cable to it.


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Ohm's law
Not just a good idea;
It's the LAW!