INSTALLATION
1. Location:
Select a location where the temperature limits of -30 to 180°F (-35 to
82°C). For standard units and -4 to 146°F (-20 to 63.6°C) for ATEX and IECEx units
will not be exceeded. Locate the switch as close as possible to the pressure source
for best response. Long lengths of piping will not affect the accuracy of the actuation
point but will increase response time.
2. Mounting:
Avoid mounting surfaces with excess vibration which could cause false
actuation when pressure is near setpoint. Attach switch with two 3/16” screws or
bolts (not included) through mounting bracket. The switch must be mounted within
20° of vertical for proper operation.
3. Pressure Connection:
The pressure connection is standard 1/4˝ or 1/2˝ female
NPT. Pipe joint sealing material should be used to insure a pressure tight joint.
4. Electrical Connections:
One or two SPDT snap switches are provided, each with
normally open contacts closing and normally closed contacts opening when
pressure increases beyond the high setpoint. The contacts reverse, returning to
their “normal” condition when pressure decreases below the low setpoint. Wire in
accordance with local electrical codes.
For convenience, two ground screws are provided. One is located inside the housing
and the other on the exterior, adjacent to the 3/4˝ NPT conduit connection. Internal
grounding terminal must be used for equipment grounding and the external terminal
is for a supplementary bonding connection where local codes or authorities permit or
requires such connection. Replace cover after wiring connections are complete.
ATEX AND IECEX INSTALLATION INSTRUCTIONS
Cable Connection
The cable entry device shall be an Ex d certified cable gland suitable for conditions of
use and correctly installed. For Tamb 63.6°C, cable gland rated ≥ 80°C shall be used.
Use cable rated 30°C higher than maximum Tamb.
Conduit Connection
An Ex d certified seal device such as a conduit seal with setting compound suitable for
conditions of use and correctly installed shall be provided immediately to the entrance
of the electrical housing. For Tamb 63.6°C, conduit seal and setting compound rated ≥
80°C shall be used. Use cable rated 30°C higher than maximum Tamb.
All wiring, conduit and enclosures must meet applicable codes for hazardous areas.
Conduits and enclosures must be properly sealed. For outdoor or other locations
where temperatures vary widely, precautions should be taken to prevent condensation
inside switch or enclosure. Electrical components must be kept dry at all times.
For units supplied with both internal ground and external bonding terminals, the ground
screw inside the housing must be used to ground the control. The external bonding
screw is for supplementary bonding
when allowed or allowed by local code. When external bonding conductor is required,
conductor must be wrapped a minimum of 180° about the external bonding screw.
Refer to Certificate No. IECEx 11.0095 X for conditions of safe use for IECEx compliant
units.
ADJUSTMENT
1. Determine the low and high setpoint pressures.
2. Connect tubing or piping from the pressure port on bottom to one leg of tee.
Connect the second leg to a pressure gage of known accuracy and in an appropriate
range. The third leg should be connected to a controllable source of pressure.
3. Connect a volt/ohm meter or other circuit tester to the snap switch terminals to
indicate when switching occurs.
4. Slowly apply pressure to the system and note the pressure at which switch
actuates. If adjustment is necessary, remove the clear plastic cover over the lower
half of the switch. It is held in place by four machine screws.
5. Adjust the low setpoint first by using a 7/16˝ open end wrench on the left, range
spring adjustment nut. As viewed from above, turn nut clockwise to increase,
counter-clockwise to decrease the low setpoint (deactuation point).
6. Adjust the high setpoint by turning the deadband spring adjustment nut, on right,
clockwise to increase, counter-clockwise to decrease, the high setpoint (actuation
point).
7. Operate the switch through several pressure cycles to confirm proper setpoint
adjustment. Replace plastic cover.
MAINTENANCE
The flame path dimensions differ from EN 60079-1 requirements. Repairs to be by
Dwyer Instruments, Inc.
The moving parts of these switches need no maintenance or lubrication. The setpoint
is the only user adjustment. On models with optional drain fitting, periodically rotate
the small captive screw from side to side several times to keep drain path clear. Units
in need of repair should be returned to the factory prepaid.
When cleaning exterior surfaces use a damp cloth to avoid
electrostatic charge.
WARNING
To prevent ignition of hazardous atmospheres, disconnect the
device from the supply circuit before opening. After disconnection,
delay 2 minutes before opening. Keep assemblies tightly closed when in use.
CAUTION
Deadband spring
adjustment nut
Range spring
adjustment nut
Limited Warranty:
The Seller warrants all Dwyer Instruments and equipment to be free from defects in workmanship or material under normal use and service for a period of one year from date of
shipment. Liability under this warranty is limited to repair or replacement F.O.B. factory of any parts which prove to be defective within that time or repayment of the purchase price at the Seller’s option
provided the instruments have been returned, transportation prepaid, within one year from the date of purchase. All technical advice, recommendations and services are based on technical data and
information which the Seller believes to be reliable and are intended for use by persons having skill and knowledge of the business, at their own discretion. In no case is Seller liable beyond replacement
of equipment F.O.B. factory or the full purchase price. This warranty does not apply if the maximum ratings label is removed or if the instrument or equipment is abused, altered, used at ratings above the
maximum specified, or otherwise misused in any way.
THIS EXPRESS LIMITED WARRANTY IS IN LIEU OF AND EXCLUDES ALL OTHER REPRESENTATIONS MADE BY ADVERTISEMENTS OR BY AGENTS AND ALL OTHER WARRANTIES, BOTH
EXPRESS AND IMPLIED. THERE ARE NO IMPLIED WARRANTIES OF MERCHANTABILITY OR OF FITNESS FOR A PARTICULAR PURPOSE FOR GOODS COVERED HEREUNDER.
Buyers Remedies:
THE BUYER’S EXCLUSIVE AND SOLE REMEDY ON ACCOUNT OF OR IN RESPECT TO THE FURNISHING OF NONCONFORMING OR DEFECTIVE MATERIAL SHALL BE TO
SECURE REPLACEMENT THEREOF AS AFORESAID, THE SELLER SHALL NOT IN ANY EVENT BE LIABLE FOR THE COST OF ANY LABOR EXPENDED ON ANY SUCH MATERIAL OR FOR ANY
SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES TO ANYONE BY REASON OF THE FACT THAT IT SHALL HAVE BEEN NON-CONFORMING OR DEFECTIVE.
CLAMP
CLAMP PLATE
SCREW
LOCKWASHER
CONDUCTOR
Front view
Side view detail
Printed in U.S.A. 11/20
FR# 442112-00 Rev. 8
©Copyright 2020 Dwyer Instruments, Inc.
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: 219-879-8000
Fax: 219-872-9057
www.dwyer-inst.com
e-mail: [email protected]
