Murphy Low Pressure SWICHGAGE 20PWC User manual

PWC-94125B
Revised 02-97
Catalog Section 05
(00-02-0033)
Low Pressure SWICHGAGE®
20PWC, 25PWC and A25PWC Series
■
For Monitoring Fuel Gas Pressure or
Engine Crankcase Pressure
■
Actuate Alarm or Shut Down System
When Abnormal Pressure Occurs
■
Combination Indicating Gage and
Critical Limit Switch
Description
The PWC Series SWICHGAGE
®
is excellent
for low pressure applications such as engine
shutdown when fuel gas pressure falls to low
level. Suitable for both natural gas or
methane–these SWICHGAGE
®
instruments
can also be used to monitor high engine
crankcase pressure (order option “H”).
The 20 and 25 series gage mechanism is
enclosed in a steel case coated to resist cor-
rosion. The 20 series has a 2 inch (51 mm)
diameter dial. The 25 series has a 2-1/2 in.
(64 mm) diameter dial.
The A25 series gage has a sealed polycar-
bonate case and includes a 2-1/2 in. (64 mm)
diameter dial.
All gages feature a polycarbonate, break-
resistant lens and a polished, stainless steel
bezel to help protect these rugged, built-to-
last instruments.
The PWC series is available in either the
SWICHGAGE
®
version with adjustable high
and/or low switch contact(s) or in the indi-
cating MURPHYGAGE
®
configuration.
The SWICHGAGE
®
incorporates an accurate
direct-reading gage with a limit switch (low
contact for fuel gas pressure; high contact for
crankcase pressure) that can be adjusted from
the front of the gage. The switch can be used to
activate alarms and/or shut down equipment.
Specifications
Ranges:
20PWC Series
• 0-4 in. H2O; single scale
• 0-10 in. H2O; single scale
• 0-20 in. H2O / 0-51 cm; dual scale
• 0-30 in. H2O / 0-76 cm; dual scale
• 0-50 in. H2O / 0-127 cm; dual scale
25PWC and A25PWC Series
• 0-30 in. H2O / 0-76 cm; dual scale
• 0-50 in. H2O / 0-127 cm; dual scale
Contact Rating: 2 A @ 30 Volts AC/DC.
Accuracy: ±3% first and last 1/3 of scale,
±2% middle 1/3 of scale.
Maximum Pressure: 2 x scale.
Process Connection: 1/8-27 NPTM brass.
Dial: White on black; single scale (inches)
and dual scale (inches/centimeters).
Limit Switch Adjustment: 1/16 hex wrench.
Mounting Hole: 2-1/16 in. (52 mm).
Bezel: Polished stainless steel.
Lens: Polycarbonate.
Mounting Studs: 10-32 UNF.
Case:
• 20PWC and 25PWC Series: Plated steel.
• A25PWC Series: Polycarbonate.
Wiring (SWICHGAGE
®
Only):
• 20PWC Series: One point,
#6 terminal block, case ground.
• 25PWC Series: Wire lead; 18 AWG x
12 in. (1.0 mm
2
x 305 mm).
• A25PWC Series: #6 terminal block.
Mounting Clamp: Plated steel.
Shipping Weight:
• 20PWC Series: 9 oz. (279 g).
• 25PWC and A25PWC Series:
11 oz. (342 kg).
Shipping Dimensions:
• 20PWC Series:
3 x 2-3/4 x 2-3/4 in. (76 x 70 x 70 mm).
• 25PWC and A25PWC Series:
4-3/4 x 4-3/4 x 2-3/4 in. (121 x 121 x 70 mm).
Warranty
A two-year limited warranty on materials and
workmanship is given with this Murphy product.
Details are available on request and are packed
with each unit.
2 and 2-1/2 in. (51 and 64 mm) Dial
20PWC-10
®
FRANK W.
MFR.
PHASED-OUT

Dimensions
Range
4 = 0-4 in. (0-10 cm)
10 = 0-10 in. (0-25 cm)
20 = 0-20 in. (0-51 cm)
30 = 0-30 in. (0-76 cm)
50 = 0-50 in. (0-127 cm)
Base Model
20PWC
20PWCG (Gage-only, no contacts)
25PWC*
25PWCG (Gage-only, no contacts)*
A25PWC*
A25PWCG (Gage-only, no contacts)*
*25 Series and A25 Series available in 0-30 in.
(0-76 cm) and 0-50 (0-127 cm) ranges only.
Options
†
B1 = Black bezel; low profile
B2 = Bezel; raised profile (was “HP”)
B3 = Black bezel; raised profile (was “HBB”)
EX = Explosion-proof
EL = Explosion-proof, less case
H = High contact only (as optional)
†Options not available on all models or configurations.
How to Order
To order, use the diagram below. NOTE: List options in ascending alphabetical order (A-Z). Example: 20PWC-H-10.
_____ – _____ – _____
A
D
C
1/16 Hex for Limit Switch
Contact Adjustment
Limit Switch
Contact
Contact
Pointer
Mounting
Clamp
Contact Wiring (SWICHGAGE®models only)
• 20PWC Series: #6 one-point terminal block
• 25PWC Series: 18 AWG x 12 in.
(1.0 mm2x 305 mm)
• A25PWC Series: #6 terminal block
1/8-27 NPTM
Connection
Mounting Hole
B
Contact Rating: 2 Amps @ 30 VAC/DC.
20PWC and 25PWC are case ground.
A25PWC is isolated ground.
HL = High and low contacts (as optional)
I = Illumination
J = Screwdriver adjustable face contact
K = Knob adjusting face contact
RP = Red tipped pointer
TP = Tamperproof contact
20PWC Series 25PWC Series A25PWC Series
A2-7/32 (56) 2-1/8 (54) 1-51/64 (46)
B1-5/16 (33) 1-3/8 (35) 1-27/64 (36)
C2-15/64 (57) 3-1/8 (79) 2-29/32 (74)
D2-1/16 (52) 2-11/16 (68) 2-11/16 (68)
NOTE: Dimensions are in inches and (millimeters).
Internal Wiring
Printed in U.S.A.
®
FRANK W.
MFR.
■ Frank W. Murphy Manufacturer
P.O. Box 470248; Tulsa, Oklahoma 74147; USA
tel. [phone] fax [phone]
e-mail [email protected]
■ Frank W. Murphy Southern Division
P.O. Box 1819; Rosenberg, Texas 77471; USA
tel. [phone] fax [phone]
e-mail [email protected]
Since 1939
■ Frank W. Murphy, Ltd.
Church Rd.; Laverstock, Salisbury SP1 1QZ; U.K.
tel. [phone] fax [phone] tlx 477088
e-mail [email protected]
■ Frank W. Murphy Pte., Ltd.
26 Siglap Drive; Republic of Singapore 456153
tel. [phone] fax [phone]
e-mail [email protected]
■ Murphek Pty., Ltd.
1620 Hume Highway; Campbellfield, Vic 3061; Australia
tel. [phone] fax [phone]
In order to consistently bring you the highest quality, full featured products, we reserve the right to change our specifications and designs at any time.
■ Murphy de México, S.A. de C.V.
Blvd. Antonio Rocha Cordero 300, Fracción del Aguaje
San Luis Potosí, S.L.P.; México 78384
tel. [phone] fax [phone]
e-mail [email protected]
■ Murphy Switch of California
P.O. Box 900788; Palmdale, California 93590; USA
tel. [phone] fax [phone]
e-mail [email protected]
■ Frank W. Murphy France
tel. [phone] fax [phone]
PHASED-OUT