Model SST–2
12/14 22804C(800) 234-4239http://www.networketi.com
4 of 8 Environmental Technology, Inc.
Location
Housed in a NEMA 4X rated enclosure, the SST fixed set point thermostat
can be mounted in either indoor or outdoor environments. The SST controller was
designed to operate in an ambient temperature range of −40° to 130°F (−40° to
55°C).
Using the integral mounting flanges, the SST is intended to be installed
on a fixed, flat, vertical surface. The mounting flanges accommodate 1/4" (6mm)
fasteners.
The SST fixed set point thermostat nonmetallic enclosure is furnished with two
3/4" (21mm) conduit entries. The conduit entry at the top left side of the enclosure is
for line voltage supply branch circuit conductors. The lower conduit entry provides
for heater load branch circuit conductors. The installed weather-tight fitting is for
the low voltage, NEC Class 2, temperature sensor. The temperature sensor may be
located up to 2,000' (610m) from the SST-2.
Supply Voltage
The SST fixed set point thermostat operates from 120, 208, 240 or 277 VAC at
50/60 Hz. For line supply and load connections, use 10 AWG or larger wires rated for
at least 75°C (167°F) at 300 VAC.
Contactor Rating
The heater contactor provides two (2) Form A (DPST) definite purpose contacts
rated for up to 30 amp AC heater loads at voltages at or below 277 VAC.
NEC Class 2 Low Voltage Connections
All low voltage wiring shall use 18 AWG or greater stranded conductors with
thermoplastic insulation rated for at least 75°C (194°F) at 300 VAC. The temperature
sensor is supplied with a 20' (6m) 2-wire jacketed cable lead. The temperature
sensor lead may be up to 500' (152.4m) using 18 AWG 2-wire jacketed cable, or up
to 2,000' (609.6m) using 12 AWG 2-wire jacketed cable.
Temperature Sensor
The temperature sensor is required for the operation of the SST. The
temperature sensor connects via wire nuts to the two blue wires in the SST
enclosure. Connect the sensor’s RED wire to either SST-2 BLUE wire and connect
the sensor’s BLACK wire to the remaining blue wire. (NOTE: It does not matter which
sensor wire is connected to which BLUE wire in the enclosure.) The sensor should
be located near the heater being controlled and is used to monitor its temperature.
Its placement is dependent upon application:
•Consider/conrmambientairtemperaturesforchillerlines,etc.
•Watersupplylines(in-lineheating)–onpipeunderinsulation
•Sprinklersystemfreezeprotection–onpipeunderinsulation
(consider pipe temperatures in unheated facilities)
