Detached Garage Subpanel and Pool Pump Bonding
A detached garage is 60 ft from a dwelling and is fed from a 60 A breaker in the main panel using schedule 40 PVC with four THWN conductors: two ungrounded, one neutral, and one equipment ground. The garage subpanel has a 20 A GFCI receptacle circuit, a 30 A circuit for a 240 V compressor, and a 240 V pool pump circuit. The pool pump is 20 ft from the garage, rated 240 V, 12 A, single-phase, with a grounded metal housing and metal conduit to a time clock. The pool has a metal ladder, a metal handrail, and a 2 ft wide concrete deck; the pump motor is not bonded. The subpanel neutral bar is bonded to the enclosure, and the equipment grounding conductor is landed on the neutral bar. The inspector also notes the pool pump is not GFCI protected and the garage receptacle is within 18 in of a utility sink.
1. Identify the feeder and subpanel grounding/bonding errors and explain the correct separation.
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The feeder has four conductors, which is correct for a detached building with a subpanel, but the subpanel is wrong. The neutral bar must be isolated from the enclosure; the equipment grounding conductor must land on a separate equipment grounding bar. Remove the bonding screw or jumper between the neutral bar and enclosure. The detached building also needs a grounding electrode system, typically a ground rod and grounding electrode conductor to the subpanel equipment ground, because it is supplied by a feeder. The metal water pipe, if any, may be an electrode only under the code conditions. Do not use the neutral as the ground. The 60 A feeder must be protected at its ampacity and the conductors must be sized for the load and voltage drop.
2. What GFCI and equipotential bonding requirements apply to the pool pump, ladder, handrail, and deck?
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The pool pump motor must have GFCI protection; the fact that it is 240 V does not exempt it. The pool also requires equipotential bonding, which is not the same as grounding. A No. 8 AWG solid copper bonding conductor must connect the pump motor, metal conduit, time clock, ladder, handrail, and other metal parts, and the pool water where required, to a common bonding grid. The concrete deck may require bonding if it contains reinforcing steel or if it is within the perimeter surface area; verify the adopted code. The equipment grounding conductor to the pump is separate and must be connected. Bonding reduces voltage gradients; it does not replace the GFCI or the EGC.
3. Is the garage receptacle location acceptable relative to the utility sink, and what needs to change?
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The garage receptacle needs GFCI protection because it is in a garage. The 18 in distance to a utility sink is not a general NEC bathroom rule; the bathroom receptacle rules apply to bathrooms, not a garage utility sink. Still, the receptacle should not be placed where it is likely to be splashed, and if it is in a damp or wet location it needs a weather-resistant receptacle and an in-use cover. Check local amendments and the manufacturer's instructions. The more serious defects are the missing pool bonding and pump GFCI; correct those before energizing. If the sink is close enough that the receptacle is in a wet location, relocate it.