Why does my voltage drop so acutely the AC's compressor switches on?

I would start by replacing ALL the wiring and circuit breakers for this particular circuit. You may have a problem with your compressor as well. But your biggest problem is the power company. This sort of performance is totally unacceptable.

I would start by replacing ALL the wiring and circuit breakers for this particular circuit. You may have a problem with your compressor as well. But your biggest problem is the power company. This sort of performance is totally unacceptable.

If the voltage regulator (stabilizer) doesn't work, and it has enough rated capacity to handle the AC, then the problem is the power from the power company. You can't do much about that aside from yelling at them. A transformer won't help, I don't think, neither will this "servo stabilizers". The physics is simple, the wire leading into your house (plus the circuit breaker, the transformer in the street, etc) is too small. For example, if it is rated at 10 amps and the AC tries to draw 20 amps, it can't be done. All a transformer or stab. will do is increase the voltage WHILE increasing the current load. Since you have limited current due to the wire size, that only makes things worse. email me if that is not clear.

A couple of things going on here. If your house is the only one in the area with this low voltage electric problem I would suspect a high resistance connection somewhere in the wiring from the transformer on down to your house wiring. I've worked similar symptoms and usually found a loose or corroded joint somewhere. This joint has much higher resistance than it should so it tends to get HOT! Look for evidence of excess heat in the wiring. Things like brittle insulation, smoke stains, rainbow colors in the wire metal (particularly copper) If aluminum wiring is used in your circuits anywhere, take a very close look at those joints as they are notorious for corroding into an insulating oxide. Aluminum wires should always be coated with an isolating electric grease and be very tightly bound to assure good contact and connections. If the joint is in the transformer, you probably don't have many options other that to request the electric company do a load test on your transformer to determine its capacity to supply the desired voltage. Might want to consider requesting this in any case as you'll see later. I'll talk a bit about the physics, then explain another possible cause for the behavior you are seeing. Motors are rated for a certain power output and voltage input. If the voltage input is low, the motor tries its best to still deliver the rated power. The only way it can do this is to allow more current to flow through itself. This shows up in the equation (Power equals volts times amps). W = EI For small drops in voltage, a slight increase in amperage can usually occur without significant damage anywhere. When you have a massive voltage drop, a lot of extra current will try to move through your wiring. More current means more heat. More heat means faster oxidation of joints already compromised. Most motors have a thermal cutout safety switch which stops current flow in cases where the windings get warmer than a certain limit. This is great for occasional use, however, when the use is chronic, there is still damage built up in the motor. The damage occurs because the thermal cutout is a temperature sensitive device, It takes time for enough heat to transfer into the sensor to trip it. In this time, the heat has already started to affect the areas closer to the source, the wires. Usually this damage shows up as enbrittlement of the insulation in the winding coils. This insulation is usually a thin coating of a varnish like substance. As the coating gets brittle combined with the motion as copper expands and contracts with the heat cycles, the insulation eventually breaks down and a loop or several in the winding are essentially shunted (short circuit). With this shunting, there are fewer coils left to develop the needed magnetic fields to operate the motor which goes hand in hand with still higher demands for current because there is less inductive resistance in the coil. Each successive heating cycle builds more damage into the system until the motor will finally be unable to start under any conditions of voltage availability. You might see how a system like this can cascade into total failure. The transformer supplying the power to your house is very similar to the motor in that it has coils creating magnetic fields. It can suffer the same problems as motors can and for the same reasons. If your transformer has bridged some insulation due to overheating or a power surge such as a lightning strike, it could be damaged to the point that it can never deliver the rated voltage it is intended to supply, even with adequate supply power coming into the transformer. Having an inadequate supply transformer coupled with a high resistance point (or too small a wire size) can compound upon one another. I know that low voltage problems are a real challenge and can be very frustrating. Hopefully your AC unit hasn't been too badly damaged yet and will work fine once you get a good voltage supply to it. Best of luck to you in your voltage hunting :)

A couple of things going on here. If your house is the only one in the area with this low voltage electric problem I would suspect a high resistance connection somewhere in the wiring from the transformer on down to your house wiring. I've worked similar symptoms and usually found a loose or corroded joint somewhere. This joint has much higher resistance than it should so it tends to get HOT! Look for evidence of excess heat in the wiring. Things like brittle insulation, smoke stains, rainbow colors in the wire metal (particularly copper) If aluminum wiring is used in your circuits anywhere, take a very close look at those joints as they are notorious for corroding into an insulating oxide. Aluminum wires should always be coated with an isolating electric grease and be very tightly bound to assure good contact and connections. If the joint is in the transformer, you probably don't have many options other that to request the electric company do a load test on your transformer to determine its capacity to supply the desired voltage. Might want to consider requesting this in any case as you'll see later. I'll talk a bit about the physics, then explain another possible cause for the behavior you are seeing. Motors are rated for a certain power output and voltage input. If the voltage input is low, the motor tries its best to still deliver the rated power. The only way it can do this is to allow more current to flow through itself. This shows up in the equation (Power equals volts times amps). W = EI For small drops in voltage, a slight increase in amperage can usually occur without significant damage anywhere. When you have a massive voltage drop, a lot of extra current will try to move through your wiring. More current means more heat. More heat means faster oxidation of joints already compromised. Most motors have a thermal cutout safety switch which stops current flow in cases where the windings get warmer than a certain limit. This is great for occasional use, however, when the use is chronic, there is still damage built up in the motor. The damage occurs because the thermal cutout is a temperature sensitive device, It takes time for enough heat to transfer into the sensor to trip it. In this time, the heat has already started to affect the areas closer to the source, the wires. Usually this damage shows up as enbrittlement of the insulation in the winding coils. This insulation is usually a thin coating of a varnish like substance. As the coating gets brittle combined with the motion as copper expands and contracts with the heat cycles, the insulation eventually breaks down and a loop or several in the winding are essentially shunted (short circuit). With this shunting, there are fewer coils left to develop the needed magnetic fields to operate the motor which goes hand in hand with still higher demands for current because there is less inductive resistance in the coil. Each successive heating cycle builds more damage into the system until the motor will finally be unable to start under any conditions of voltage availability. You might see how a system like this can cascade into total failure. The transformer supplying the power to your house is very similar to the motor in that it has coils creating magnetic fields. It can suffer the same problems as motors can and for the same reasons. If your transformer has bridged some insulation due to overheating or a power surge such as a lightning strike, it could be damaged to the point that it can never deliver the rated voltage it is intended to supply, even with adequate supply power coming into the transformer. Having an inadequate supply transformer coupled with a high resistance point (or too small a wire size) can compound upon one another. I know that low voltage problems are a real challenge and can be very frustrating. Hopefully your AC unit hasn't been too badly damaged yet and will work fine once you get a good voltage supply to it. Best of luck to you in your voltage hunting :)