IMP117 11
2
DEVICE CAN BE MOUNTED IN ANY ORIENTATION BUT
VERTICAL MOUNTING IS RECOMMENDED TO PREVENT
MOISTURE FROM ENTERING THE ENCLOSURE.
CONSIDER THE USE OF A PRESSURE SNUBBER IF
SEVERE PRESSURE SURGES ARE EXPECTED.
FOR PRESSURE MODELS, MOUNT VIA PRESSURE
CONNECTION. ALWAYS USE A WRENCH ON PRESSURE
CONNECTION HEX. DO NOT TIGHTEN BY TURNING
THE ENCLOSURE AS THIS WILL DAMAGE THE SENSOR
AND WEAKEN WELDED JOINTS.
FOR DIFFERENTIAL PRESSURE MODELS, MOUNT
USING A WRENCH ON LOW AND HIGH SIDE PRESSURE
CONNECTION HEX OR MOUNT AGAINST A RIGID SUPPORT
THEN CONNECT LOW AND HIGH PRESSURE PORTS.
Controls may be mounted and operated in any
position. They may be surface mounted via the
two mounting ears on either side of the enclosure,
or directly to a rigid pipe by using the pressure
connection. Low pressure and differential pressure
units, models 520-535, 540-543, 544-548, are also
available with an optional surface mounting bracket.
Should the control be installed where condensation
is expected, vertical mounting is recommended as a
means of keeping water away from switch terminals.
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.
DO NOT EXCEED ELECTRICAL RATINGS LISTED ON
NAMEPLATE. OVERLOAD ON A SWITCH CAN CAUSE
FAILURE, EVEN ON THE FIRST CYCLE.
ENSURE ELECTRICAL CONDUIT ENTRIES ARE
PROPERLY SEALED TO PREVENT MOISTURE ENTRY.
❶
Remove the two screws retaining the cover and cover gasket.
❷
A 1/2” NPT conduit connection is provided on the left hand
side of the enclosure. Two cast-in 7/8” diameter knockouts for
electrical conduit are located on the side and back of enclosure
(see dimensional drawings). These can easily be knocked out by
placing a blade of a screwdriver in groove and tapping sharply
with a hammer. The terminal block terminals are clearly labeled
“Common”, “Normally Open” and “Normally Closed”.
For optional switches supplied with leadwires, the
following color coding applies:
SPDT
DPDT
Circuit 1
Circuit 2
Common
Violet
Violet
Yellow
Normally Closed
Black
Black
Red
Normally Open
Blue
Blue
Orange
A grounding screw and clamp (cast in symbol) is
provided which meets a 35 lb. pull test. Keep the
wire as short as possible to prevent interference
with the plunger.
Part II - Adjustments
•
5/8” Open End Wrench
ALL MODELS HAVE A TWO-PIECE ADJUSTABLE PLUNGER
(SEE FIGURE 1). THIS FEATURE IS CHARACTERIZED BY A
3/16” HEX SCREW INSTALLED IN THE 1/4” HEX PLUNGER.
FOLLOW THE SET-POINT PROCEDURE BELOW TO AVOID
DISTURBING THE GAPPING. GAPPING IS FACTORY-SET
AND CRITICAL TO THE FUNCTION OF THE SWITCH. THE
GAPPING PROCEDURE SHOULD ONLY BE PERFORMED IF
THE PLUNGER WAS ACCIDENTALLY ADJUSTED.
For set point adjustments and recalibration, connect
control to a calibrated pressure source.
❶
Remove cover.
❷
Loosen Phillips screw adjustment lock. Adjust set point by
turning 5/8” hex adjustment screw clockwise (left) to raise set
point, or counter clockwise (right) to lower set point. Tension on
adjustment screw can be increased by tightening adjustment
lock onto it. (See Figure 1). Controls include uncalibrated
reference scales for high, low or mid range settings. When
making adjustments, do not exceed the proof pressure rating
on nameplate as this may cause a shift in set point.
NOTE:
Models 190-194 and 490-494 (welded stainless
steel diaphragms).These models are application
sensitive. For rising pressure applications, set point
should be adjusted from low pressure up to set
point.
For falling pressure applications set point should
be adjusted from high pressure down to set point.
Wide pressure cycling above and below set point
can cause control band shift.
AFTER COMPLETING SETTING ADJUSTMENT, BE SURE
TO REINSTALL ENCLOSURE COVER.
Re-Gapping Procedure
(refer to Figure 1)
•
5/8”Open End Wrench
•
3/6” Open End Wrench
•
1/4” Open End Wrench
Plunger Screw
(3/16” Hex)
FACTORY SET
DO NOT ADJUST
unless re-gapping
is necessary
Hex Plunger
(1/4” Hex)
Set-point Adjustment Screw
(5/8” Hex)
Adjustment Lock
Figure 1
