Mercoid A1F Series Installation and operating instructions

Series A1F Compact OEM Pressure Switch
Specications - Installation and Operating Instructions
Bulletin IN-92
The SERIES A1F Compact OEM Pressure Switch is ideal for panel mounting wherever
a high-quality, economical open-case or weatherproof control is required.
INSTALLATION
1. Location: Select a location where the temperature limits of -40 to 180°F (-40 to
82°C) will not be exceeded. Locate the switch as close as possible to the pressure
source. Long lengths of piping will not affect accuracy of the actuation point but will
slightly add to response time.
2. Mounting and Processing Connection: Avoid mounting surfaces with excess
vibration which could cause false actuation when pressure is near setpoint. The
switch should be mounted within 20° of vertical for proper operation. Mount the
switch by connecting it to the process piping using either 1/4˝ NPT female or 1/2˝
male connection. Pipe joint compound or TFE thread tape should be used to prevent
leakage.
3. Electrical Connections: The SPDT snap switch includes normally open, normally
closed and common connections. The common and normally open contacts will close
and the common and normally closed contacts will open when pressure increases to
the setpoint. The actions will reverse when pressure decreases below the setpoint
minus the deadband. A green grounding screw is provided on the switch bracket. All
wiring should be in accordance with local codes.
SPECIFICATIONS
Service: Compatible liquids and gases.
Wetted Materials: Pressure Chamber: 316 SS; Diaphragm: Fluorocarbon.
Temperature Limit: -40 to 175°F (-40 to 80°C).
Pressure Limits: 500 psig (34 bar).
Enclosure Rating: No rating for open construction. Installed properly within an
optional A-447 enclosure meets NEMA 4X standards.
Switch Type: SPDT snap switch.
Electrical Rating: 15A @ 120/240/480 VAC, 1/8 HP @ 125 VAC, 1/4 HP @ 250
VAC.
Electrical Connection: Screw terminals.
Process Connection: 1/4˝ female NPT and 1/2˝ male NPT.
Mounting Orientation: Within 20° of vertical.
Set Point Adjustment: Knurled screw cap with indicating scale.
Deadband: Fixed, See deadband chart.
Weight: 10.5 oz (297 g).
ø1-53/64
[ø46.43]
SET POINT
ADJUSTMENT CAP
SPDT SNAP
SWITCH
INSULATIVE BARRIER
(OPEN ON TOP) (3) ELECTRICAL
TERMINALS
GROUND
SCREW
1-7/16
[36.51]
1/2 NPT
(MALE CONNECTION)
1/4 NPT
(FEMALE CONNECTION)
3-3/4
[95.25]
5-7/16
[138.11]
1-29/32
[48.41] 4-11/16
[119.06]
1-1/2
[38.10]
4
[101.6]
1-17/32
[38.89] 3-1/16
[77.79]
A1F A1F with A-447
MERCOID
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: [phone]
Fax: [phone]
www.dwyer-inst.com
e-mail: [email protected]
A DIVISION OF
DWYER INSTRUMENTS, INC.
By Dwyer

©Copyright 2015 Dwyer Instruments, Inc. Printed in U.S.A. 12/15 FR# 440838-10 Rev. 3
SETPOINT ADJUSTMENT
1. Determine the setpoint pressure. The approximate actuation point can be set by
turning the adjustment cap up or down, aligning the top of the O-ring, located above
the cap, with the appropriate scale graduation.
2. Connect tubing or piping from the pressure port on bottom of switch to one leg
of a tee. Connect the second leg to a pressure test 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 action terminals to
indicate when switching occurs.
4. Slowly apply pressure to the system and note the pressure at which switching
occurs.
5. Operate the switch through several cycles to conrm proper actuation point.
6. Remove test apparatus and attach switch to pressure source and control circuit
wiring. Place switch in service.
Example of how to order:
A1F - O - SS - 1 - 4
1 2 3 4 5
1. Diaphragm Designation:
F - Fluorocarbon
2. Enclosure Designation:
O - Open Construction No Enclosure
3. Housing Material Designation:
SS - 316SS
4. Switch Designation:
1 - SPDT Snap Action Switch
5. Operating Pressure Range Designation:
1 - 2 to 15 psig
2 - 4 to 75 psig
3 - 8 to 225 psig
4 - 16 to 450 psig
MAINTENANCE
Upon nal installation of the Series A1F Compact OEM Pressure Switch, no routine
maintenance is required. A periodic check of the system calibration is recommended.
The Series A1F is not eld serviceable and should be returned if repair is needed
(eld repair should not be attempted and may void warranty). Be sure to include a
brief description of the problem plus any relevant application notes. Contact customer
service to receive a return goods authorization number before shipping.
DEADBAND CHART-PSIG (BAR)
Range
Deadband at
Minimum Range
Deadband at
Maximum Range
2 to 15 (0.14 to 1.03)
4 to 75 (0.28 to 5.17)
8 to 225 (0.55 to 15.5)
16 to 450 (1.1 to 31.0)
2 (0.14)
4 (0.27)
8 (0.55)
15 (1.0)
3 (0.21)
15 (1.0)
25 (1.7)
50 (3.5)
MERCOID
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: [phone]
Fax: [phone]
www.dwyer-inst.com
e-mail: [email protected]
A DIVISION OF
DWYER INSTRUMENTS, INC.