480VAC Motor Drive Fed with just L1 & L2 (No L3)

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jkinzieh

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Earth, NA, USA, Wisconsin
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Electronic, Industrial , Instrumentation, Controls, Technician
Howdy, new User... let me know rules/etiquette as necessary
Existing system uses 480VAC, only L1 & L2 to Drive Power input?
Never seen this config. before

L1 -------------- |..Yaskawa V7..| -------------- |.............. | -------------- | .......1 HP.. |
L2 -------------- |........Drive........| -------------- |...O/L's...| -------------- | ..MOTOR |
L3........ N/C .........| ......................... | -------------- |................| -------------- | .................. |

This is currently running in a Polymer Pump application.
There is a Sister system next to this one that is NOT running that I need to fix
 
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petersonra

Senior Member
Location
Northern illinois
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engineer
It is not unusual to do this. Most smaller drives can be configured to allow for it. I don't know why people do it. I guess they think it's cheaper than having an extra fuse, but they need a bigger drive to do it.
 
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winnie

Senior Member
Location
Springfield, MA, USA
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Electric motor research
This is intentional and useful when you only have single phase available. The drive rectifies the input power to DC and then uses the DC to create the synthesized output.

Using single phase input means more current on the 2 lines used and more ripple on the DC bus, and as petersonra states you generally need a larger size drive for a given output capability.

It would seem very silly to use this sort of capability if you have 3 phase available.

-Jon
 
Besoeker3

Besoeker3

Senior Member
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UK
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Retired Electrical Engineer
petersonra said:
It is not unusual to do this. Most smaller drives can be configured to allow for it. I don't know why people do it. I guess they think it's cheaper than having an extra fuse, but they need a bigger drive to do it.
Click to expand...
Two larger fuses, two larger conductors as opposed three smaller fuses and smaller conductors. Can be done I suppose but not something I have done.
 
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jkinzieh

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Thanks!!! I'm an old FAART, and never saw that config. :confused:
Follow up question...
Do you think there would there be an associated PARAMETER, or possible jumper/switch setting? needing to be set for an electrical configuration like this one?

I'm going to get the manual/parameter listing for the Yaskawa V7 which is working West Pump and review. To the system I have to repair, Someone took out a GPD333 and installed a Yaskawa A1000 in the East Pump Ctrl Cab.
 
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jkinzieh

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Location
Earth, NA, USA, Wisconsin
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Electronic, Industrial , Instrumentation, Controls, Technician
infinity said:
1 HP, 480 volts 3 phase? Is it not possible that this is a single phase motor?
Click to expand...
No
... How to I attach an image, I have a pic of the Motor Name plate
here is name plate info on the working System

[TD valign="top"]
Motor- Nameplate​
[/TD]
[TD valign="top"]PE EQP III-XS[/TD]

[TD valign="top"]
Model # - or Cat No​
[/TD]
[TD valign="top"]B3/44FLF1BMHDR[/TD]

[TD valign="top"]
HP​
[/TD]
[TD valign="top"]0.75[/TD]

[TD valign="top"]
Volts/Hz​
[/TD]
[TD valign="top"]460/60[/TD]

[TD valign="top"]
Poles​
[/TD]
[TD valign="top"]4[/TD]

[TD valign="top"]
Amps​
[/TD]
[TD valign="top"][/TD]

[TD valign="top"]
RPM​
[/TD]
[TD valign="top"]1760[/TD]

[TD valign="top"]
FR#​
[/TD]
[TD valign="top"]143T[/TD]

[TD valign="top"]
S.F.​
[/TD]
[TD valign="top"]1.15[/TD]
 
GeorgeB

GeorgeB

ElectroHydraulics engineer (retired)
Location
Greenville SC
Occupation
Retired
jkinzieh said:
Do you think there would there be an associated PARAMETER, or possible jumper/switch setting? needing to be set for an electrical configuration like this one?

I'm going to get the manual/parameter listing for the Yaskawa V7 which is working West Pump and review. To the system I have to repair, Someone took out a GPD333 and installed a Yaskawa A1000 in the East Pump Ctrl Cab.
Click to expand...
As to why, only reason I can see reasonably is if the drives are a long distance from the supply and wire cost made it preferable; perhaps existing cable? Currents will be low, under 2A to the motor, difficult to guess to the drive, but certainly less than 5A.

Configuration ... if the "new" drive hasn't ever run in the application, it may be configured to require all phases, not unusual. It probably can either by jumper or configuration be set to allow phase loss (missing).

Think about the relatively common application to get 3 phase from single phase supplies which is usually with 115 or 230 input and uses a voltage doubler for the 115 applications. These then run 208/230 wound motors.
 
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jkinzieh

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Location
Earth, NA, USA, Wisconsin
Occupation
Electronic, Industrial , Instrumentation, Controls, Technician
Jraef

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
Why I have done this exact thing in the past:

Replacing a 120V 1/2HP reversible motor that needed to be bumped to 1HP, existing 14ga wires already in the conduit. 480V was available, which cut the current so that we could use the existing wire, then the cost of a small 480V drive was almost the same as a single phase reversing motor starter. VFD converts to 3 phase, simpler reversing setup, re-use existing wire run.
 
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