Thank you all for taking the time to look at this, hopefully this is simple to answer.
I have a Class I Div 1, groups C&D/Class I Div 2, groups B&C rated solenoid operated pneumatic valve installed in a Class I Div 2 group B area.
The Coil - 7watts, 24vdc with 3 conductor flying leads using CI D2 stamped FMC with rated fittings into a NEMA 12 Box which houses CI D2 rated feed through terminal blocks.
From the j-box, PLTC hazardous location rated multi conductor cable through a CI D2 rated gland back to a PLC discrete, sourcing, individually isolated, 1amp output channel. The PLC is inside an enclosure which is purged and also uses rated gland penetrations.
The power supply is less than 1000VA (Sec. 725) output which provides power to the output modules. Each sub bus is overcurrent protected but not each channel. There can be more than one channel on a sub bus but not more than 8 amp quick blow fuses per sub bus supplying no more than one output module.
The solenoid catalog data sheets provide the need for barriers on the FM IS coil they provide as an alternate but for the CI D1/2 rated coil they don't mention a barrier. The coil housing is threaded which I assume is an expected seal off for C1 D1 or a rated fitting for CI D2.
From 500.7, the PLC enclosure is purged (D), the solenoid is rated for use in the area and the manufacturer states NEMA7 and NEMA9 for the solenoid. I believe this is all appropriate.
From 501.10(B)(1)(3) - PLTC in accordance with article 725 within cable tray terminated with listed fittings looks correct.
From 501.10(B)(2)(4) - Liquid tight with flexible metal conduit with approved fittings looks correct.
Another engineer I work with is stating I need an isolation barrier between the PLC output and the solenoid.
I don't see code requirements for an additional barrier.
Am I missing something in the code that would drive an isolation barrier? The manufacturer does not seem to require an isolation barrier.
I have a Class I Div 1, groups C&D/Class I Div 2, groups B&C rated solenoid operated pneumatic valve installed in a Class I Div 2 group B area.
The Coil - 7watts, 24vdc with 3 conductor flying leads using CI D2 stamped FMC with rated fittings into a NEMA 12 Box which houses CI D2 rated feed through terminal blocks.
From the j-box, PLTC hazardous location rated multi conductor cable through a CI D2 rated gland back to a PLC discrete, sourcing, individually isolated, 1amp output channel. The PLC is inside an enclosure which is purged and also uses rated gland penetrations.
The power supply is less than 1000VA (Sec. 725) output which provides power to the output modules. Each sub bus is overcurrent protected but not each channel. There can be more than one channel on a sub bus but not more than 8 amp quick blow fuses per sub bus supplying no more than one output module.
The solenoid catalog data sheets provide the need for barriers on the FM IS coil they provide as an alternate but for the CI D1/2 rated coil they don't mention a barrier. The coil housing is threaded which I assume is an expected seal off for C1 D1 or a rated fitting for CI D2.
From 500.7, the PLC enclosure is purged (D), the solenoid is rated for use in the area and the manufacturer states NEMA7 and NEMA9 for the solenoid. I believe this is all appropriate.
From 501.10(B)(1)(3) - PLTC in accordance with article 725 within cable tray terminated with listed fittings looks correct.
From 501.10(B)(2)(4) - Liquid tight with flexible metal conduit with approved fittings looks correct.
Another engineer I work with is stating I need an isolation barrier between the PLC output and the solenoid.
I don't see code requirements for an additional barrier.
Am I missing something in the code that would drive an isolation barrier? The manufacturer does not seem to require an isolation barrier.
