Hammond SKT011409NC Normally Closed Thermostat, Fahrenheit Scale

The SKT011409NC is a normally closed (NC) enclosure thermostat with a Fahrenheit scale, from the SKT Series. It provides air temperature control and monitoring in cabinets and is the version used with heaters and heater fans: its contact opens when rising temperature reaches the set point, shutting the heater off. Electricians and panel builders use it to automate enclosure heating instead of leaving heaters powered continuously.

A thermostatic bi-metal sensor drives a snap-action contact, adjustable from 30 to 140°F (0 to 60°C). The switching difference (hysteresis) is + or - 4°F (+ or - 3 K), and the NC setting knob carries a red imprint. The switching capacity is 15A @ 120VAC, 10A @ 240VAC, and 30W @ DC, and noise suppression is class N according to VDE 0875.

The ordering table gives dimensions of 2.8 x 1.5 x 1.4 (height x width x depth); the short description lists 2.41 x 1.3 x 1.4 in. The housing is flame retardant UL94V0 plastic in gray, protected to IP20, with a 2 pole terminal for AWG 14 (2.5 mm²) wire. The thermostat clips onto 35 or 38 mm DIN rail with the included clip.

The instructions call for installation by qualified staff, in the upper part of the cabinet as far as possible from heat-creating components, without covering the ventilation slots. When setting an NC thermostat, add the highest possible hysteresis to the required minimum temperature. The SKT011409NC is UL Recognized Component, cUL Recognized Component and CE approved, RoHS and REACH compliant, and ships at 0.2 lb (0.09 kg).