leitmotif
Member
Ok so where I now work is food industry. Workrooms are chilled so we got condensation. Water all over and enthusiastic cleanup employees with water hoses
- if it is there HOSE IT DOWN
these guys would make good firemen.
Equipment (mostly motors) voltages commonly are 120 VAC single phase and 90 or 180 VDC and for three phase 208 240 and 480.
My main concern is the control circuits many of which are 240.
I know this is no longer allowed by NFPA 79 and even if that were not the case I don't like "hi voltage" control. SO I gotta start advocating 120 VAC control voltage or less for AC equipment at least. DC motors from what I have seen (so far) are all driven with solid state controllers.
In my mind 120 VAC motors should be on GFCI - that will be separate battle.
SO for 240 VAC or higher
IT seems to me with all this water and even with an isolation transformer (properly fused grounded etc) for 120 VAC control I should also use a GFCI. That way if something goes wrong the GFCI will trip and we do not have runaway equipment or electrocuted employee.
Just the control transformer may be enough battle.
IF I use 24 VDC or 24 VAC then I would not have to go thru the battle for the GFCI.
Have not decided which just yet probably AC since more equipment is built for 24 VAC than for 24 VDC.
Am I thinking straight
- any good devil advocate advice
or better ideas?
Thanks
Dan Bentler
- if it is there HOSE IT DOWN
these guys would make good firemen.
Equipment (mostly motors) voltages commonly are 120 VAC single phase and 90 or 180 VDC and for three phase 208 240 and 480.
My main concern is the control circuits many of which are 240.
I know this is no longer allowed by NFPA 79 and even if that were not the case I don't like "hi voltage" control. SO I gotta start advocating 120 VAC control voltage or less for AC equipment at least. DC motors from what I have seen (so far) are all driven with solid state controllers.
In my mind 120 VAC motors should be on GFCI - that will be separate battle.
SO for 240 VAC or higher
IT seems to me with all this water and even with an isolation transformer (properly fused grounded etc) for 120 VAC control I should also use a GFCI. That way if something goes wrong the GFCI will trip and we do not have runaway equipment or electrocuted employee.
Just the control transformer may be enough battle.
IF I use 24 VDC or 24 VAC then I would not have to go thru the battle for the GFCI.
Have not decided which just yet probably AC since more equipment is built for 24 VAC than for 24 VDC.
Am I thinking straight
- any good devil advocate advice
or better ideas?
Thanks
Dan Bentler