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#1 Robert

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Posted 07 November 2006 - 01:37 PM

Installed a Westinghouse Vectrol soft star with an older logic board on a three phase 480 volt delta 100 hp
motor that run a skilift. and get a phase loss when unit is activated . the conrol is fed through a 3 phase control transformer and i think the problem is due to the kicker leg that is showning 480 volt to ground and
un balancing my control voltage and causing my fault .
i was hopping someone has a sullution to this problem or do i have an other problems.


#2 jraef

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Posted 07 November 2006 - 03:43 PM

Unfortunately, the Vectrol product has been obsolete for over 10 years now that I know of. The original Vectrol, prior to being bought by Westinghouse, was re-spawned as Motortronics 23 years ago although Westinghouse used the name for years afterwards. The product designs may be similar and if they are, the Motortronics soft starters pick up Phase Loss only by current, nothing to do with voltage. The criteria is not having at least 20% current flowing through one (or more) of the CTs within 3 seconds after a start command is issued. So if the motor connected is too small to pull at least 20% of the rated current, you will get this phase loss indication. An example in your case might be that you have your 100HP motor connected to a 150HP 220A rated starter, but it is clutch connected (as many ski lifts are), so the unloaded current of that 100HP motor is only 40A, which is less that 20% of 220A. That is the most common problem. Also a broken CT connection would do it, as well as the obvious issues of one or more of the motor leads being disconnected or too high of resistance. Other than that, there is nobody left that I know of who can service or troubleshoot a Vectrol starter any more. Motortronics used to have a few old timers that might have been able to help, but they are all gone now.

It might be time to invest in a new one.
"He's not dead, he's just pinin' for the fjords!"

#3 Robert

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Posted 08 November 2006 - 11:42 AM

QUOTE(jraef @ Nov 7 2006, 10:43 AM) View Post

Unfortunately, the Vectrol product has been obsolete for over 10 years now that I know of. The original Vectrol, prior to being bought by Westinghouse, was re-spawned as Motortronics 23 years ago although Westinghouse used the name for years afterwards. The product designs may be similar and if they are, the Motortronics soft starters pick up Phase Loss only by current, nothing to do with voltage. The criteria is not having at least 20% current flowing through one (or more) of the CTs within 3 seconds after a start command is issued. So if the motor connected is too small to pull at least 20% of the rated current, you will get this phase loss indication. An example in your case might be that you have your 100HP motor connected to a 150HP 220A rated starter, but it is clutch connected (as many ski lifts are), so the unloaded current of that 100HP motor is only 40A, which is less that 20% of 220A. That is the most common problem. Also a broken CT connection would do it, as well as the obvious issues of one or more of the motor leads being disconnected or too high of resistance. Other than that, there is nobody left that I know of who can service or troubleshoot a Vectrol starter any more. Motortronics used to have a few old timers that might have been able to help, but they are all gone now.

It might be time to invest in a new one.




The phase loss come on the minute the units power is turned on.


#4 chaterpilar

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Posted 08 November 2006 - 02:44 PM

Robert,

Phase loss means the starter is getting low/no current in any/each of the phases, the phase loss monitoring is done even before the starter is ON.

Check the following things.

1. Input to starter ( all phases balanced) before starting.

2. If there is any isolator between Softstarter and the motor, check it for loose/burnt conncetions or it is switched OFF.

3. Check loose connections at the terminal box of motor.

Cheterpilar

#5 Robert

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Posted 10 November 2006 - 12:21 PM

have double checked all connections.
the Vectrol softstart has a transformer for control voltage across the three phases .
the unit rateing 460 volts and the delta that iam feeding it with is 490 volts phase to phase.
the reading to ground is two phases 230volts and the kicker leg reads 460 to ground could this be
giving me a inproper voltage on the control side of the tansformer this unit worked fine on a 480/277 y configeration.

#6 jraef

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Posted 11 November 2006 - 01:57 AM

It shouldn't matter. If it is anything like the later designs, the only thing that transformer is for is to detect the zero-cross points on the incoming line in order to determine the pulse firing time references. It shouldn't even be looking at phase to ground voltages because they were all designed to work on any system, Y or Delta. At least Motortronics was and the same people designed both products. Maybe Westinghouse changed something in the design after the original people split off to form Motortronics, but I doubt it. When I worked at Motortronics they would occasionally still get calls from Westinghouse for help on the Vectrols until they were obsoleted.

Since it is happening immediately when you energize it as opposed to when you tell it to run, you probably have some kind of component failure on the board. Companies such as Electrical South may still have the board diagrams to be able to repair it, might be worth a call. If you want to test it out first, find a 480VY277 system and see if you get the same fault, or make your own with a couple of small transformers just for testing.
"He's not dead, he's just pinin' for the fjords!"

#7 Robert

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Posted 11 November 2006 - 11:10 AM

Thank you for the info will give them a call in the mean time we got a new soft start
and will look at this unit to be repaired




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