weressl
Esteemed Member
...and more common than common senseandinator said:
Arc Flash
- Thread starter cb3
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ItsHot
Senior Member
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- A little piece of heaven!
resume?
resume?
resume?
I did not know you need a resume to do residential? But then again there is a lot that I do not know, "know it alls" in this line of work tend to be dangerous!andinator said:
If anyone has accidently browsed this thread trying to learn something about ARC FLASH they might want to try http://www.arcflashforum.com
Andy_Sanchez
Member
- Location
- *845*
Fellows,
I don't know where this should be located at but, I am concerned about a device that is going into production.
It involves a 5 HP 480 motor and 3 phase on /off switch rated at 30 amps.
Albeit this device may be used with the typical contactor setup, however my area of concern is that the typical end user has the possibilty to connect it directly to a 480 source, and subject themselves to Arc Flashing IF the snap switch fails, or when in a damp environment.
Iv'e seen alot of changes in my 20+ years in the field, but this one raises my hackles.
I need your advise on this before someone gets hurt.
I don't know where this should be located at but, I am concerned about a device that is going into production.
It involves a 5 HP 480 motor and 3 phase on /off switch rated at 30 amps.
Albeit this device may be used with the typical contactor setup, however my area of concern is that the typical end user has the possibilty to connect it directly to a 480 source, and subject themselves to Arc Flashing IF the snap switch fails, or when in a damp environment.
Iv'e seen alot of changes in my 20+ years in the field, but this one raises my hackles.
I need your advise on this before someone gets hurt.
weressl
Esteemed Member
Andy_Sanchez said:
I really can't make heads or tails out of this.
Could you try to explain what exactly is your concern?
Try to use the Code picture in front of 430.2 to identify the components by their proper name, such as means of disconnect, etc. Describe source-to-load the components in order, identify the components missing or used inproperly in both cases and state what your concern is.
davidr43229
Senior Member
- Location
- Columbus, Oh
I think both Zog and Weressl are on the right track for 2009:
FPN No. 1: A flash hazard may exist when energized electrical conductors or circuit parts are exposed or when they are within equipment in a guarded or enclosed condition, provided a person is interacting with the equipment in such a manner that could cause an electric arc.
If the gear has been properly "maintained" and the owner can provide records to this effect, PPE may not be required. It's when Equipment has not been maintained that, in & of itself, it presents "unknowing" potiential Arc Flash Hazzard and PPE is then required per the picture that Weressl provided earlier.
I also would agree with Weressl that too many owners have expanded/modified and not paid attention to the existing "Withstand Rating" of the OCPD.
Additionally per UL489 for MCCB, the rating into a fault up to 100amps used to be only "1" trip, They added a "Buss-shot" test, so now the total is "2" trips.
Just my $.02
FPN No. 1: A flash hazard may exist when energized electrical conductors or circuit parts are exposed or when they are within equipment in a guarded or enclosed condition, provided a person is interacting with the equipment in such a manner that could cause an electric arc.
If the gear has been properly "maintained" and the owner can provide records to this effect, PPE may not be required. It's when Equipment has not been maintained that, in & of itself, it presents "unknowing" potiential Arc Flash Hazzard and PPE is then required per the picture that Weressl provided earlier.
I also would agree with Weressl that too many owners have expanded/modified and not paid attention to the existing "Withstand Rating" of the OCPD.
Additionally per UL489 for MCCB, the rating into a fault up to 100amps used to be only "1" trip, They added a "Buss-shot" test, so now the total is "2" trips.
Just my $.02
I called Andy_Sanchez at his place of employ and spoke at length (arms), LOL.
His situation is that his Engineering Team is trying to devise an accessory for a three headed floor grinding machine. It consists of three 5 HP 3450RPM motors, powered by a Baldor VFD. That portion is within NEC guidelines as far as I saw. The Engineering Team is building a single bowl grinder that is to be plugged to the load side of the VFD. This device is comprised of a 8AWG line cord with a Hubble 30 3phase 480 plug that ties into the VFD. The method of switching is a 30 amp three pole snap switch that feeds the 5 HP motor, NO OVERCURRENT PROTECTION. His situation is, this device can be plugged independently from the VFD and straight to a 480 source. It' only means of disconnect is the snapswitch. If it fails, there could be a potential. It looks like 430. is not adhered to.
IMO, a control contactor, 480/120 xfrmr and a method of switching via a momentary handle switch would be safer.
BTW He's my younger Brother, (17 minutes)
His situation is that his Engineering Team is trying to devise an accessory for a three headed floor grinding machine. It consists of three 5 HP 3450RPM motors, powered by a Baldor VFD. That portion is within NEC guidelines as far as I saw. The Engineering Team is building a single bowl grinder that is to be plugged to the load side of the VFD. This device is comprised of a 8AWG line cord with a Hubble 30 3phase 480 plug that ties into the VFD. The method of switching is a 30 amp three pole snap switch that feeds the 5 HP motor, NO OVERCURRENT PROTECTION. His situation is, this device can be plugged independently from the VFD and straight to a 480 source. It' only means of disconnect is the snapswitch. If it fails, there could be a potential. It looks like 430. is not adhered to.
IMO, a control contactor, 480/120 xfrmr and a method of switching via a momentary handle switch would be safer.
BTW He's my younger Brother, (17 minutes)
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