A guide to Perske's KNS, KCS, KRS, KS and VS series

Perske high-frequency motors have been the first choice of the woodworking industry for routing, shaping and finishing for decades: stiff spindles, precision double bearings, ground and hardened shafts, and radial and axial run-out the maker specifies at 8 microns or better. The range is wide, and the model numbers are terse. Here is how to read them.

The series

• KNS — compact high-frequency routing motors; in our catalogue 0.37 to 7 HP. See the KNS series.
• KCS — routing motors with a collet nose; in our catalogue 4 to 11.5 HP. See the KCS series.
• KRS and KRSV — narrow, rectangular housings for machines where the motors sit close together; 1 to 4 HP in stock or to order. See the KRS and KRSV series.
• KS — the heavy end of the range; in our catalogue 15 to 30 HP. See the KS series.
• VS — versatile routing and finishing motors; in our catalogue 1.35 to 7 HP. See the VS series.

Reading the nameplate

A Perske plate and the matching print carry everything a repair or a replacement needs:

• Voltage: two families in our catalogue. Mains-frequency motors are plated 230/460 V; the true high-frequency motors are plated 220/380 V for a converter.
• Speed and frequency: read them together. A mains-frequency plate says 3,600 rpm at 60 Hz, the two-pole speed; on a converter the same motor turns 60 rpm per hertz, so 300 Hz is 18,000 rpm. A high-frequency plate says it directly: 18,000 rpm at 300 Hz, or 18,000/21,600 rpm at 300–360 Hz. Never run a motor past the maximum speed on its print.
• Print number: the drawing the motor was built to (MS 630B, MS 652AM and so on). Quote it and there is no ambiguity about shaft, nose or mounting.
• T-box location and thread hand: whether the terminal box sits left or right at the front, and whether the shaft thread is right- or left-hand. Two motors with the same series and size can differ only here, which is why our listings spell it out.

Ordering one

If you are replacing a motor, photograph the plate and send it with your enquiry: series, size, print number, voltage, T-box side and thread hand. If a model is not in stock we can usually source it; the product page says so when it is on the shelf.

If the motor is repairable, it is usually cheaper and quicker to rebuild it. We stock the common Perske bearing sets.