IMT120 15
2
DEVICE MUST NOT BE ALTERED OR MODIFIED
AFTER SHIPMENT. CONSULT UE IF MODIFICATION IS
NECESSARY.
The 120 Series temperature switch utilizes either a
liquid filled sensing stem (immersion stem, direct
mounting) or liquid filled sensing bulb (bulb &
capillary, remote mounting) to detect a temperature
change. The response at a pre-determined set
point(s), actuates a SPDT, dual SPDT, or DPDT snap-
acting micro switch(es), converting the temperature
signal into an electrical signal. Control set point(s)
may be varied by turning the adjustment hex (C120,
F120) or the external knob(s) and pointer(s) (B121,
B122, E121, E122, 820E, 822E) according to the
procedures outlined (See Part II - Adjustments).
Please refer to the product technical datasheet at
www.ueonline.com for product specifications. Date
code format on nameplate is “YYWW” for year and week.
Part I - Installation
•
Screwdriver
•
Adjustable Wrench to 1-1/2”
Mounting
INSTALL DEVICE WHERE SHOCK, VIBRATION AND
TEMPERATURE FLUCTUATIONS ARE MINIMAL. DO NOT
INSTALL DEVICE IN AMBIENT TEMPERATURES THAT
EXCEED PUBLISHED LIMITS ON THE NAMEPLATE.
DEVICE IS PROVIDED WITH TWO 3/4” NPT ELECTRICAL
CONDUIT OPENINGS, EITHER OF WHICH OR
BOTH CAN BE USED DURING INSTALLATION. A
3/4” EXPLOSION-PROOF PLUG IS PROVIDED FOR
PROPERLY PLUGGING THE UNUSED CONDUIT
OPENING. THE EXPLOSION-PROOF PLUG MUST BE
PROPERLY INSTALLED AND IS CERTIFIED AS PART
OF THE DEVICE AND CARRIES NO INDIVIDUAL
MARKINGS.
DO NOT KNOCKOUT ANY PLUGS ON EXPLOSION-
PROOF TYPES 820E OR 822E.
THE CONNECTION OF THE DEVICE SHALL BE MADE
BY CABLE ENTRIES OR A STOPPING BOX SUITABLE
FOR THE CONDITIONS OF USE AND CORRECTLY
INSTALLED, AND CERTIFIED BY TYPE OF EXPLOSION
PROTECTION - FLAMEPROOF ENCLOSURE ‘d’.
DEVICE SHOULD BE MOUNTED TO PREVENT
MOISTURE FROM ENTERING THE ENCLOSURE.
VERTICAL MOUNTING IS RECOMMENDED.
ALWAYS USE A WRENCH ON LOCAL MOUNT,
IMMERSION STEM HEX (SEE DIMENSIONAL
DRAWINGS). DO NOT TIGHTEN BY TURNING THE
ENCLOSURE AS THIS WILL DAMAGE THE SENSOR AND
WEAKEN WELDED JOINTS.
The conduit connection must be properly sealed
(potted) for horizontal installation. Device may be
surface mounted via the four 1/4” screw holes on the
enclosure or mounting bracket.
Type 820E and 822E
Units must be surface mounted. Drill mounting
holes per Figure 1.
IF A SEAL FITTING IS REQUIRED, INSTALL THE
NIPPLE AND THE SEAL FITTING PRIOR TO SURFACE
MOUNTING THE CONTROLLER.
Mounting Bulb and Capillary
Fully immerse the bulb and 6” of capillary in the con-
trol zone. For best control it is generally desirable to
place the bulb close to the heating or cooling source
in order to sense temperature fluctuations quickly.
Be sure to locate the bulb so it will not be exposed to
temperature beyond the device range limits. If a sepa-
rable well or union connector is used follow separate
instructions included with them.
AVOID BENDING OR COILING THE CAPILLARY TUBE
TIGHTER THAN 1/2” RADIUS. EXERCISE CAUTION
WHEN MAKING BENDS NEAR THE CAPILLARY END.
Wiring
DISCONNECT ALL SUPPLY CIRCUITS BEFORE
WIRING DEVICE. WIRE DEVICE IN ACCORDANCE
WITH LOCAL AND NATIONAL ELECTRICAL CODES.
MAXIMUM RECOMMENDED WIRE SIZE IS 14 AWG AND
RECOMMENDED TIGHTENING TORQUE FOR FIELD
WIRING TERMINALS IS 7 TO 17 IN-LBS. IT IS IMPERATIVE
TO USE PROPERLY RATED EXPLOSION-PROOF SEALING
FITTINGS FOR ELECTRICAL WIRE ENTRY.
FIELD WIRING MUST BE RATED 90°C (194°F)
MINIMUM. FOR AMBIENT TEMPERATURES BELOW
-10°C (14°F), USE SUITABLE FIELD WIRING.
DO NOT EXCEED ELECTRICAL RATINGS LISTED ON
NAMEPLATE. OVERLOAD ON A SWITCH CAN CAUSE
FAILURE, EVEN ON THE FIRST CYCLE.
THE INTERNAL GROUNDING TERMINAL SHALL BE USED
AS THE PRIMARY EQUIPMENT GROUNDING MEANS. THE
EXTERNAL GROUNDING TERMINAL IS NOT TO BE USED
AS THE PRIMARY EQUIPMENT GROUNDING TERMINAL
AND IS ONLY FOR SUPPLEMENTAL (SECONDARY)
GROUNDING WHERE LOCAL AUTHORITIES PERMIT OR
REQUIRE SUCH A CONNECTION.
CLEARANCE FOR
1/4 SCREW
4 PLACES
Figure 1:
820E, 822E Mounting
6 3/8
161.9 mm
9
228.6 mm
