Buying a Used Compressor or Motor at Shershah: What to Test Before You Pay

Shershah doesn't only trade scrap by weight. A working section of the market deals in used machinery, compressors, motors, and generator parts pulled from equipment that's been decommissioned rather than destroyed, and these sell by function and condition, not by kilo. Buying one without checking it first is the single most common way people lose money here.

Compressors: listen before you buy

An AC or refrigeration compressor that's been sitting disconnected for a while can seize, and a seized compressor is scrap, not a working part, regardless of how clean it looks externally. Ask the seller to run it if there's any way to do so on the spot, even briefly on a test rig some shops keep for exactly this. A compressor that hums evenly and doesn't draw an obviously high current is a far safer bet than one nobody can demonstrate running.

Motors: check the shaft and the windings

Spin the motor shaft by hand before anything else. It should turn smoothly with no grinding, no obvious play side to side, and no resistance that feels like a bearing has failed. If you can see the windings (the copper coils inside), look for scorch marks or a burnt smell, both signs the motor has been run hot at some point and may fail again under load even if it currently spins freely.

Generators and generator parts

A generator sold as a whole unit is a bigger commitment and deserves an actual test run under some load, not just an idle start, since a generator that idles fine can still fail to hold voltage once you put a real appliance on it. If the seller won't run it under load before you pay, that's a reasonable point to negotiate the price down to account for the risk, or walk away.

Rust and corrosion tell you about storage, not just age

Surface rust on a housing doesn't necessarily mean the internals are bad, equipment stored outdoors rusts regardless of how well it was maintained. But rust that's reached moving parts, a shaft, bearing housings, electrical terminals, is a different and more serious sign, since corrosion there directly affects function rather than just appearance.

The basic rule

Anything with a motor or a compressor in it should be tested running, not just inspected sitting still, before you hand over money. Sellers who deal honestly in this section of the market are used to being asked and won't be offended. The ones who resist a test are telling you something.