Variable Frequency Drives

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Old 02-17-17, 05:20 PM
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Variable Frequency Drives

Unsure if I am in the right forum sub-cat but need advice on wiring a variable frequency drive to operate a commercial cheese grater with a 3-phase motor from a single phase 240VAC supply. I can provide specifics if anyone here has the knowledge and ability to help?
 
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Old 02-17-17, 05:24 PM
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This is the correct forum and there are many here that can help.

Posts pictures. http://www.doityourself.com/forum/el...-pictures.html
Post links.
Post any info you have.
 
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Old 02-17-17, 05:49 PM
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I have a 30A dedicated 240V supply to run to the VFD(Lenze 2.00 HP SMVector-ESV152N02YXB) and the used commercial cheese grater(Palazzolo Mfg Model GS-1 - 2HP; 208/230V; 6.5/6.2A; 3PH; 60HZ) was wired with a 4-prong grounding plug. My Questions are as follows:
1.) I know the connection from the grater(motor) must be direct to the VFD but currently has 4 wires (red-black-white-ground) attached to the 4-prong plug. Should I run 10/3 from the 30A Breaker to the VFD and thus utilize all 4 wires from the motor to the VFD?
2.) If my assertion in question 1 above is correct can you help as to the correlation of wire color from the motor wiring to the VFD? The VFD wire designations at the motor connection terminals have U V W PE so, are there correlations for the red, black and white motor wires(realizing the PE terminal is for the ground in both locations? Does U correspond to the L1 supply; V to L2 and W to L3?
 
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Old 02-17-17, 06:05 PM
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You're trying to connect a three phase motor to a single phase service..... correct ?
 
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Old 02-17-17, 06:06 PM
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VFD Connetion terminalsName:  20170217_195103A.jpg
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Old 02-17-17, 06:10 PM
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Motor specifics labelName:  20170217_121812A.jpg
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Old 02-17-17, 06:14 PM
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Yes that is correct, I am trying to connect the three phase equip. motor to single phase supply
 
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Old 02-17-17, 06:15 PM
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User manual for those following along.
walker industrial/Lenze-AC-Tech/SMVector-User-Manual.pdf


You would use this diagram.....
Name:  esv.JPG
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L1 and L2 are your 240v supply and PE is the ground.
10-2 from panel to VFD.
 
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Old 02-17-17, 06:32 PM
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Got it. So, the white and black leads both go to double pole 30A Circuit breaker and no neutral to neutral bar in this application?
 
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Old 02-17-17, 06:37 PM
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That is correct. Neutral is not required.

The installation manual says #12 is ok and to use a 25A circuit breaker.
I recommend staying with #10 and it may be pretty hard to find a 25A breaker
so the next size up is allowed.... 30A.
 
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Old 02-17-17, 06:44 PM
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Great, thank you! Can you help with the wiring from the motor to the VFD as well? Do I just need to use the black, red and green leads from the motor wire (black to U terminal; red to V terminal and green to PE and white to W orleave the white unused here?
 
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Old 02-17-17, 06:54 PM
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If you are using rubber cable it needs to be 12-4 or larger.

The three colors red, black and white go to T1, T2 and T3 in no particular order.*
The green connects to PE.

Very important..... make sure green IS actually connected at grater.

If you are using a plug between the VFD and the grater..... then that is considered a service disconnect. If it's going to be hardwired directly..... you will then need a disconnect just before and located next to the VFD drive. There must be a way to kill power to service the system.

* If the VFD has forward and reverse listed on it and the grater is running backwards or if the grater is running backwards....... interchange any two L wires on the L1-L2-L3 side..... like L1 and L2... and that will reverse the direction.
 
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Old 02-17-17, 07:53 PM
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OK makes sense. I thought I had read there was not supposed to be a ''disconnect' between the VFD and motor but, if that is acceptable, I will leave the wire/4-prong setup already attached to the motor and go from the VFD to a mating receptacle. Last question, in this scenario, do I need a 10/3 run between the VFD and receptacle so that T1, T2, T3 ground are all going from VFD to receptacle thus to all 4 prongs in existing plug(see attached)Name:  20170203_133024C.jpg
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Old 02-17-17, 08:13 PM
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The disconnect I mentioned would be before the VFD. Technically that's where it should be but you would rarely need to service the VFD.

So... a plug is also considered a disconnect means so that you can unplug the machine before servicing it. They don't want you to unplug the machine with the VFD turned on.

Yes.... you need to wire from the VFD to the receptacle. I would use the same size as the rubber cord.
 
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Old 02-17-17, 08:19 PM
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OK, the rubber cord from motor to plug is marked '4/C 16AWG' and all 4 wires are connected at the plug. So....you're saying go with the same size rubber cord and attach all 4 wires to 'motor' terminals on VFD and receptacle?
 
 

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