Pressure
2-1/2 [63.50]
2-1/16 [52.39]
2 [50.80]
1-1/4
[31.75]
(4) 6-32 HOLES
EQUALLY SPACED ON
A 5-1/8 [130.18] B.C.
Ø4-47/64
[120.25]
Ø5
[127.00]
Ø4 [101.60]
FAC E
5-1/2 [139.70]
O.D.
MOUNTING
RING
5/8 [15.88]
5/8 [15.88] PANEL
MAX
3/16 [4.76]
3-7/8 [98.43]
5-1/8 [130.18]
6-3/8 [161.93]
(7-5/8 [193.68])
4-3/8 [111.13]
HOUSING REMOVAL
3/4 CONDUIT
CONNECTION
Ø4-3/4
[120.65]
3-7/8 SQ
[98.43]
1/8 FEMALE NPT HIGH
PRESSURE CONNECTION
1/8 FEMALE NPT LOW
PRESSURE CONNECTION
Series
A3000
Photohelic®Pressure Switch/Gages
3-in-One Indicating Gage, Lo-Limit and Hi-Limit Control
Series A3000
Photohelic
Switch/Gage.
®
Set points are instantly
adjusted with front knobs.
Photohelic®Switch/Gages function as versatile, highly repeatable
pressure switches combined with a precise pressure gage employing the
time-proven Magnehelic
®
design. The Photohelic®measures and controls
positive, negative or differential pressures of air and compatible gases.
Standard models are rated to 25 psig (1.7 bar) with options to 35 (2.4) or
80 (5.5 bar) psig. Single pressure 36000S models measure to 6000 psig
(413 bar) with a 9000 psig (620 bar) rating.
Two phototransistor actuated, DPDT relays are included for low/high limit
control. Easy to adjust setpoint indicators are controlled by knobs located
on the gage face. Individual setpoint deadband is one pointer width — less
than 1% of full scale. Setpoints can be interlocked to provide variable deadband — ideal for control of fans, dampers, etc. Gage reading is continuous
and unaffected by switch operation, even during loss of electrical power.
Choose from full scale pressure ranges from a low 0-.25" (0-6 mm) w.c. up
to 30 psi (21 bar); single positive pressure to 6000 psig (413 bar).
PHOTOHELIC SENSING — HOW IT WORKS
In typical applications, these Dwyer switch/gages control between high
and low pressure set points. When pressure changes, reaching either set
point pressure, the infrared light to the limiting phototransistor is cut off
by the helix-driven light shutter. The resulting phototransistor signal is
electronically amplified to actuate its DPDT slave relay and switching
occurs. Dead band between make and break is 1% of full scale or less — just
enough to assure positive, chatter-free operation.
RELAY-TRANSFORMER FEATURES
A plastic housing protects all electronic components. Solid-state and integrated circuit electronics are on glass-epoxy printed circuit boards and
self-extinguishing terminal boards (for the Series A3000 only).
APPLICATIONS — PHOTOHELIC SWITCH/GAGES
In both series of pressure switch/gages, you get the convenience of a
visual indication plus high-low limit switching. For both OEM and inplant applications, the Photohelic
®
switch/gage is used to control pressures in air conditioning systems, clean rooms, fluidic and pneumatic
control systems, materials handling equipment, alarm or control fume
exhaust systems, control pressure in air structures, and monitor respiratory and blood pressures.
Dwyer Instruments, Inc./P.O. Box 373/Michigan City, IN 46361/Phone 219 879-8000/Fax 219 872-9057 • U.K. Phone (+44) (0)1494-461707 • Australia Phone 61 2 4272-2055
26
SPECIFICATIONS
GAGE SPECIFICATIONS
Service: Air and non-combustible, compatible gases.
Wetted Materials: Consult factory.
Accuracy: ±2% of full scale at 70°F (21.1°C). ±3% on -0 and ±4% on -00
models.
Pressure Limits: -20" Hg. to 25 psig (-0.677 to 1.72 bar). MP option; 35
psig (2.41 bar), HP option; 80 psig (5.52 bar). 36003S – 36010S; 150 psig
(10.34 bar). 36020S and higher;1.2 x full scale pressure.
Temperature Limits: 20 to 120°F.
(-6.67 to 48.9°C) Low temperature option available.
Process Connections: 1/8˝ female NPT.
Size: 4˝ (101.6 mm) dial face, 5˝ (127 mm) O.D. x 8-1/4˝ (209.55 mm).
Weight: 4 lb (1.81 kg).
SWITCH SPECIFICATIONS
Switch Type: Each setpoint has 2 Form C relays (DPDT).
Repeatability: ±1% of full scale.
Electrical Rating: 10A @ 28 VDC, 10A @ 120, 240 VAC.
Electrical Connections: Screw terminals.
Power Requirements: 120 VAC, 50/60 Hz; 240 VAC & 24 VAC Power
optional.
Mounting Orientation: Diaphragm in vertical position. Consult factory for
other position orientations.
Set Point Adjustment: Adjustable knobs on face.
Agency Approvals: UL, CSA, CE.
STANDARD MODEL
Two phototransistor-actuated circuits and two DPDT relays permit both high and low
alarms or limit controls. Relays are de-energized when gage pointer is to the left of respective
set points; relays are energized as pointer passes to the right of set points. Loss of electrical
power or loss of pressure provide “fail safe” protection.
OPTIONS
Single contact, right set point, for actuation on increasing or decreasing pressure.
OEM Model, less relay and transformer components and housing but including infrared
diodes and phototransistor(s), light shutter and set pointer(s). For single or double contact.
Remote-Mounted Relay, relay pack may be mounted remotely from gage. Standard
length is 5 ft. For other lengths, specify cable length required.
Tamper-proof knobs, low temperature option, special scales, voltages and other features and modifications are available.
Special Housings available include Weatherproof (NEMA 4) and Explosion-proof
(NEMA 7 CD, 9 EFG; NEC Class I, DIV. 1 & 2, Groups C, D, Class II, Div. 1 & 2, Groups
E, F, G, Class III. Contact Customer Service for detailed dimension drawings.
HIGH AND LOW LATCHING CIRCUITS
Dwyer Photohelic
high-low latching circuits. That is, the equipment will hold in these respective positions
once activated and until manually reset. This can be particularly useful for alarm and signal
applications where control is accomplished by another Photohelic
means. Complete wiring and operational instructions are included. Where manual reset is
required a dry circuit push button such as Dwyer Part A-601 should be used.
®
switch/gages can be wired for high-latching, low-latching or combination
®
switch/gage or other
Check these features for dependable control
Bezel and front cover (with set
point knobs and zero adjustment
screw) removed to expose
Photohelic®set point mechanism.
Cover is clear polycarbonate plastic.
Gage pointer and light shutter
are mounted on helix and balancing counterweight. Shutter passes
through slot in optical limit switch to
expose phototransistors to integral
infrared light source or mask them
depending on applied pressure.
Light shield effectively protects
phototransistors from strong outside light sources yet allows free
pointer movement. It also gives
interior a clean “finished” look.
Optical limit switches are used
for reliability and long service life.
Attached directly to set pointers,
they are individually aligned to
assure precise switching accuracy.
Semi-Flexible drive shaft connects to set point knobs.
Zero adjustment screw connects to screw in cover to adjust
zero pressure reading.
Pressure
Plastic enclosure protects electronic components and electrical
connections.
Polycarbonate connection or
terminal board is self-extinguishing
(A3000 only).
Glass-epoxy printed circuit
boards for durability and perfor-
mance.
Load relays are DPDT with latch-
ing feature for maximum application
versatility.
Electronics are designed to operate on 50/60 Hz, 120 volt current
with 10% over or under voltage.
Special units for other voltages are
available.
Switch set pointers show switch
settings at all times.
Spring loaded friction clutch
prevents operator damage of set
point mechanism.
Patent No. 3,862,416
MODELS AND RANGES — SERIES A3000 PHOTOHELIC®SWITCH/GAGES
NOTE: Special models can be built to OEM customers' specifications with scales reading in special pressure units like
ounces per square inch, inches of mercury, etc. Square Root Scales reading in FPM or SCFM are also available. Custom
logos and special graduations can also be included. Contact factory for minimum quantities and pricing.
STOCKED MODELS in bold
Model
Number
A3000-00
A3000-0
A3001
A3002
A3003
A3004
A3005
A3006
A3008
A3010
A3015
A3020
A3025
A3030
A3040
A3050
A3060
A3080
A3100
A3150
Bi-Directional Range
A3000-00N
Zero Center Ranges
A3300-0
A3301
A3302
A3304
A3310
A3320
A3330
Range,
In W.C.
0-.25
0-.50
0-1.0
0-2.0
0-3.0
0-4.0
0-5.0
0-6.0
0-8.0
0-10
0-15
0-20
0-25
0-30
0-40
0-50
0-60
0-80
0-100
0-150
.05-.20
.25-0-.25
.5-0-.5
1-0-1
2-0-2
5-0-5
10-0-10
15-0-15
Model
Number
A3201
A3202
A3203
A3204
A3205
A3210**
A3215**
A3220**
A3230***
**MP or ***HP option standard
Photohelic®— Single Pressure
A36003S
A36006S
A36010S
A36020S
A36030S
A36060S
A36100S
A36300S
A36600S
Model
Number
A3000-00AV
A3000-0AV
A3001AV
A3002AV
A3010AV
Pitot tube required
Range,
0-30
0-60
0-100
0-200
0 300
0-600
0-1000
0-3000
0-6000
Range In W.C./
Air Velocity,
F.P.M.
0-.25/300-2000
0-.50/500-2800
0-1.0/500-4000
0-2.0/1000-5600
0-10/2000-12500
PSI
0-1
0-2
0-3
0-4
0-5
0-10
0-15
0-20
0-30
Model
Number
A3000-6MM
A3000-10MM
A3000-25MM
A3000-50MM
A3000-80MM
A3000-100MM
Zero Center Ranges
A3300-20MM
A3300-30MM
Model
Number
A3000-15CM
A3000 20CM
A3000-25CM
A3000-50CM
A3000-80CM
A3000-100CM
A3000-150CM
A3000-200CM
A3000-250CM
A3000-300CM
Zero Center Ranges
A3300-4CM
A3300-10CM
A3300-30CM
Options and Accessories — Add options as a suffix. Example: A3001-LT
-SRH, Single Relay Activates on Increase .......... -MP, Medium pressure ..........................
-SRL, Single Relay Activates on Decrease ........ -HP, High pressure ................................
-OLS, OEM model.......................................... -LT, Low temperature (-20
-RMR, Remote mounted relay........................ A-298 Flat Flush Mounting Bracket .......
-TAMP, Tamper proof knobs .......................... A-601, Manual reset switch...................
Range,
MM W.C.
0-6
0-10
0-25
0-50
0-80
0-100
10-0-10
15-0-15
Range,
CM W.C.
0-15
0-20
0-25
0-50
0-80
0-100
0-150
0-200
0-250
0-300
2-0-2
5-0-5
15-0-15
Model
Number
A3000-60PA
A3000-125PA
A3000-250PA
A3000-500PA
A3000-750PA
A3300-250PA
A3300-500PA
Model
Number
A3000-1kPA
A3000-1.5kPA
A3000-2kPA
A3000-3kPA
A3000-4kPA
A3000-5kPA
A3000-8kPA
A3000-10kPA
A3000-15kPA
A3000-20kPA
A3000-25kPA
A3000-30kPA
A3300-1kPA
A3300-3kPA
Range,
Pascals
0-60
0-125
0-250
0-500
0-750
Zero Center Ranges
125-0-125
250-0-250
Range,
Kilopascals
0-1
0-1.5
0-2
0-3
0-4
0-5
0-8
0-10
0-15
0-20
0-25
Zero Center Ranges
0-30
.5-0- .5
1.5-0-1.5
o
F).................
Dwyer Instruments, Inc./P.O. Box 373/Michigan City, IN 46361/Phone 219 879-8000/Fax 219 872-9057 • U.K. Phone (+44) (0)1494-461707 • Australia Phone 61 2 4272-2055
27