User:Surryroger/sandbox

Delta 23-660 slimline 6 inch bench grinder. This article is intended to aid in the repair of this model bench grinder with the following start run characteristics. Slow start up, low power when at work (grinding), noisy when running.

There are few user serviceable parts with-in this motor circuit, but there is a AC capacitor which can cause this problem, and can be replaced by the user, if he/she has common mechanical skills.

Skills/ tools required: Use of a screwdriver, wire stripper / knife, crimping tool for wire connectors and / or soldering skills, and multimeter skills.

Theory: Located in the base, under the motor there is a capacitor which is in series with a second winding. Technically, this is a shaded pole motor, and the capacitor shifts the phase for that winding to provide start / run torque. If the capacitor either shorts, or opens, the motor can either fail to start, or run poorly.

Diagnosis: IMPORTANT: unplug / remove power from the grinder before attempting any repair/ diagnosis! Remove the metal shield on the base plate by removing the 4 rubber feet/screws. This will reveal the wiring. There are two leads from the motor windings which exit the motor case, and attach to the capacitor by means of crimp-on connectors. Disconnect the capacitor at the junctions, taking care to save as much lead on the capacitor as possible, in case this is not the problem, and you want to re-install it. Set the meter to read Ohms RX10 or RX100 scale should be OK. Connect one lead of your test meter to one lead of the capacitor, and touch the other to the remaining lead of the capacitor while observing the meter. The meter should momentarily indicate some resistance, then fade down. Quickly reversing the leads will show the same or greater movement, again reverting to infinity (High resistance). This indicates the capacitor is functioning correctly (charging and discharging). If the capacitor indicates a short or low resistance, or exhibits no charging, it warrants replacement. Note: Use of a analog meter better displays this test, than a digital meter will.

Although the manufacturer indicates this capacitor as discontinued, it is a common component, and available at motor repair shops as well as electrical supply outlets or online. The ratings should be stamped on the capacitor, most likely 10 UF and 250 WVAC (working Volts Alternating Current). It should be noted that this is a AC capacitor, and not a DC capacitor, the latter being unsuited for this application.