By Barry Stone
Dear Barry,
An inspector in my area faulted an air conditioner for not having an electrical disconnect switch. I called an air conditioning contractor to repair the condition (not a free service call, I might add) and he found that the disconnect switch was not missing: It was simply installed inside the air conditioner. If the home inspector had taken time to remove the exterior panel, he would have found the switch. What do you think about this situation? - Jan
Dear Jan,
Your question brings up a safety issue which may not be fully understood by some inspectors and contractors, but which is familiar to most licensed electricians.
Air conditioners, by code, must have a disconnect switch that is visible and readily accessible. Additionally, the code allows the switch to be on or inside the fixture, as stated by your air conditioning contractor. That seems simple enough at first glance and, seemingly, should bring finality to the debate. But the simplicity ends as we begin to explore the matter further.
Most air conditioning contractors express strong disapproval of internal switches on air conditioners, regardless of the code. In fact, the majority of A/C contractors have never installed an inside switch and would strongly advise others against doing so. To understand this position, we should consider the purpose for requiring a disconnect switch.
The primary intent of the National Electric Code "is the practical safeguarding of persons and property from hazards arising from the use of electricity." In keeping with this intent, the power to an air conditioner should be turned off when the fixture is being serviced or repaired. If a disconnect switch is installed on the outside of the unit, a contractor or technician can turn off the power before commencing work on the system. But what happens when an A/C system has a short circuit, and the switch is installed on the inside? The contractor then must handle the system with the power turned on. The outer casing must be removed in order to gain access to the switch, with the possible result of injury (or worse) to the workman.
Recognition of this hazard is common among air conditioning contractors. That is why external disconnect switches are the standard of the industry. Internal switches are extremely rare and are regarded by home inspectors everywhere as a significant "red-flag" condition.
In those instances where inside switches are installed, strict electric code requirements apply, and violations of these are common. In some instances, switches are installed in relay boxes, a condition that voids the manufacturer's warranty. Additionally, a switch must be compatible with the horsepower rating of the motor and must be rated to open if the motor is drawing "locked-rotor current." Esoteric, to say the least; requiring the expertise of a qualified electrical specialist.
Dear Barry,
An inspector in my area faulted an air conditioner for not having an electrical disconnect switch. I called an air conditioning contractor to repair the condition (not a free service call, I might add) and he found that the disconnect switch was not missing: It was simply installed inside the air conditioner. If the home inspector had taken time to remove the exterior panel, he would have found the switch. What do you think about this situation? - Jan
Dear Jan,
Your question brings up a safety issue which may not be fully understood by some inspectors and contractors, but which is familiar to most licensed electricians.
Air conditioners, by code, must have a disconnect switch that is visible and readily accessible. Additionally, the code allows the switch to be on or inside the fixture, as stated by your air conditioning contractor. That seems simple enough at first glance and, seemingly, should bring finality to the debate. But the simplicity ends as we begin to explore the matter further.
Most air conditioning contractors express strong disapproval of internal switches on air conditioners, regardless of the code. In fact, the majority of A/C contractors have never installed an inside switch and would strongly advise others against doing so. To understand this position, we should consider the purpose for requiring a disconnect switch.
The primary intent of the National Electric Code "is the practical safeguarding of persons and property from hazards arising from the use of electricity." In keeping with this intent, the power to an air conditioner should be turned off when the fixture is being serviced or repaired. If a disconnect switch is installed on the outside of the unit, a contractor or technician can turn off the power before commencing work on the system. But what happens when an A/C system has a short circuit, and the switch is installed on the inside? The contractor then must handle the system with the power turned on. The outer casing must be removed in order to gain access to the switch, with the possible result of injury (or worse) to the workman.
Recognition of this hazard is common among air conditioning contractors. That is why external disconnect switches are the standard of the industry. Internal switches are extremely rare and are regarded by home inspectors everywhere as a significant "red-flag" condition.
In those instances where inside switches are installed, strict electric code requirements apply, and violations of these are common. In some instances, switches are installed in relay boxes, a condition that voids the manufacturer's warranty. Additionally, a switch must be compatible with the horsepower rating of the motor and must be rated to open if the motor is drawing "locked-rotor current." Esoteric, to say the least; requiring the expertise of a qualified electrical specialist.
For us non-specialists, the bottom line is this: Internal switches are unusual and are often installed in questionable ways -- good reasons for home inspectors to wave the proverbial red flag wherever inside switches are suspected. Conditions cited by home inspectors may not always prove to be truly defective, but when electrical compliance is in doubt, a wise inspector will always err on the side of safety.
