Dwyer DH3 User Manual

Bulletin B-30

Series DH3 Digihelic®Differential Pressure Controller

Specifications - Installation and Operating Instructions

DWYER INSTRUMENTS, INC.

P.O. BOX 373 • MICHIGAN CITY, IN 46360, U.S.A. Fax: [phone] e-mail: [e-mail]

Phone: [phone] www.dwyer-inst.com

DIMENSIONS

(4) 6-32 HOLES

EQUALLY SPACED ON A

5-1/8 (130.18) B.C.
PANEL MOUNTING

1/8 FEMALE NPT LOW

PRESSURE CONNECTION

1/8 FEMALE NPT HIGH

PRESSURE CONNECTION

2-1/16

(52.39)

2

(50.80)

1-1/4

(31.75)

ø4-47/64
(120.25)

Ø5

(127.00)

Ø4 (101.60)

FACE

5-1/2 (139.70) O.D.

MOUNTING RING

5/8 (15.88)

PANEL MAX

2-1/2

(63.50)

3/16

(4.76)

1/8 FEMALE NPT HIGH
PRESSURE CONNECTION

1/2

(

12.70)

1-9/32

(32.54)

1

1/16

(17.46)

30°

1-3/4

(44.45)

1/2 (12.70)

11/16

(17.46)

1/8 FEMALE NPT LOW

PRESSURE CONNECTION

(3) Ø3/16 (4.77) HOLES EQUALLY
SPACED ON A 4-1/8 (104.78) B.C.
SURFACE MOUNTING

SPECIFICATIONS
Service: Air and non-combustible, compat-

ible gases.

Wetted Materials: Consult factory.
Housing Material: Die cast aluminum

case and bezel.
Accuracy: ±1.5% for 0.25˝ and ±0.25˝ w.c.
ranges. Ranges 0.5˝ to 5˝ w.c. and corre­sponding bi-directional (except ±2.5˝ w.c.):
±1%; All other ranges: ±0.5% @ 77°F
(25°C) including hysteresis and repeatabili­ty (after 1 hour warm-up).

Stability: < ±1% per year.
Pressure Limits: Ranges

≤ 2.5˝ w.c.: 25 psi; ±2.5˝, 5˝ w.c.: 5 psi;
10˝: w.c. 5 psi; 25˝ w.c.: 5 psi; 50˝ w.c.: 5
psi; 100˝ w.c.: 9 psi.
Temperature Limits: 32 to 140°F (0 to
60°C).
Compensated Temperature Limits: 32 to
140°F (0 to 60°C).
Thermal Effects: 0.020%/°F (0.036/°C)
from 77°F (25°C). For 0.25˝ and ±0.25˝
w.c. ranges: ±0.03%/°F (±0.054%/°C).

Power Requirements: 12-24 VAC/VDC.
Power Consumption: 3 VA max.

Output Signal: 4-20 mA DC into 900

ohms max.
Zero & Span Adjustments: Accessible via
menus.
Response Time: 250 ms (dampening set
to 1).
Display: Backlit 4 digit LCD 0.4˝ height
LED indicators for set point and alarm sta­tus.
Electrical Connections: 15 pin male high
density D-Sub connection. 18˝ (46 cm)
cable with 10 conductors included.
Process Connections: 1/8˝ female NPT.
Side or back connections.
Mounting Orientation: Mount unit in verti­cal plane.
Size: 5˝ (127 mm) O.D. x 3-1/8˝ (79.38
mm).

Weight: 1.75 lbs. (794 g).
Agency Approvals: CE.

SWITCH SPECIFICATIONS
Switch Type: 2 SPDT relays.
Electrical Rating: 1 amp @ 30 VAC/VDC.
Set Point Adjustment: Adjustable via key-

pad on face.

2

INSTALLATION

1-1/2

[38.1]

5/16

[7.94]

11/16

[17.46]

3/4

[19.05]

1-3/32

[27.78]

1-3/4

[44.45]

1/2 [12.70]

(3) Ø3/16 [4.77] HOLES EQUALLY
SPACED ON A 4-1/8 [104.78] B.C.

Ø1/2 [12.70] HOLE FOR
LOW PRESSURE CONNECTION

Ø1/2 [12.70] HOLE FOR
HIGH PRESSURE CONNECTION

LOCATION: Select a clean, dry location free from shock and vibration where temperature
limits will not be exceeded. Distance from the transmitter to the receiver is limited only by
total loop resistance. See ELECTRICAL CONNECTIONS. Tubing feeding pressure to the
instrument can be practically any length required, but long lengths will increase response
time slightly.

POSITION: All standard models are calibrated for use in a vertical mounting position.
Higher range models will perform properly at other angles but should be spanned and
zeroed in the position in which they will be used. Because of their sensitivity to gravitation­al forces, models with ranges under 1˝ w.c. (25.4 mm w.c.) must always be mounted ver­tically.

PRESSURE CONNECTIONS: For installation convenience two sets of 1/8˝ female NPT
pressure ports are supplied. Be sure to seal the unused ports with pipe plugs included.

Positive Pressure - Connect tubing to HIGH PRESSURE port and vent LOW PRESSURE
port to atmosphere.

Negative (Vacuum) Pressure - Connect tubing to LOW PRESSURE port and vent HIGH
PRESSURE port to atmosphere. (When operating this device in a dusty environment,
install an optional A-331 Filter Vent Plug in the vented port to keep interior clean.)

Differential Pressure - Connect tubing from the higher source to HIGH PRESSURE port
and from the lower source to LOW PRESSURE port.

Fig. A

3

MOUNTING: The DH 3 may be either panel (flush) mounted or surface mounted.

Ø4-3/4 [120.65] HOLE

PNEUMATIC
PRESSURE TAPS

SNAP RING

GROOVE

Panel Mounting - Cut a 4-13/16˝ or 122 mm diameter hole in the panel and insert the unit
from the front. Slip on the mounting ring with the stepped side facing rear. Next, fit the snap
ring into the narrow groove at back edge of bezel. Thread four (6) 32 x 1-1/4˝ mounting
screws into tapped holes in mounting ring and set it against snap ring. Tighten screws
against rear of panel. See Fig. B.

Fig. B

Surface Mounting - Drill (3) 3/16˝ (4.76 mm) diameter holes for mounting and cut a 9/16˝

x 1-1/2˝ (14.3 x 38.1 mm) opening for access to terminal block as indicated in Fig. B. If rear
pressure connections are to be used, also provide 1/2˝ diameter holes as shown in Figs.
A and C. Insert 6-32 machine screws from rear of mounting surface, thread into tapped
holes on back of transmitter and tighten.

Fig. C

4

WIRING

The DH 3 uses a standard 15 pin male high density D-Sub connector available from
most electronic distributors. A pre-wired 18˝ cable is included with each unit.
See below table for cable color wiring information.

Function

15 PIN Connector

Cable Color

Terminal

12-24 VAC/VDC Power
12-24 VAC/VDC Power
4-20mA XMTR Output ­4-20mA XMTR Output +
SP1 Relay N/O
SP1 Relay Com
SP1 RELAY N/C
SP2 or ALarm Relay N/O
SP2 or ALarm Relay Com
SP2 or ALarm Relay N/C

1. If 12-24 VDC power is used, the polairty is unimportant.

2. Wire in accordance with an equivalent national standard or code. Use copper conduc­tors only rated for 60°C.

3. All terminals are rated CLASS 2.

4. ISOLATION: All inputs and outputs to each other: 500 VAC.

5. 4-20 mA Transmitter – Check the specifications for the device receiving this signal for
input resistance. Typical 250 to 600 OHMS, 600 OHMS maximum.

1
6
2
11
12
13
14
15
10
5

NOTES:

Brown
Yellow
Black
Red
Vilolet
Grey
White
Blue
Green
Orange

5

SP/ALSP/AL

M

ENUMENU

EE

RSTRST

KEY FUNCTIONS

INWCINWC

1.0001.000

SP1SP1

SP2SP2

ALHIALHI

ALLOALLO

SP/ALSP/AL

RSTRST

MENUMENU

EE

X1KX1K

FRONT PANEL

ALARM
DESCRIPTOR

UNITS

I

NPUT VALU E

MULTIPLIER

DESCRIPTOR

VISABLE WITH

SOME VELOCITY

A

ND FLOW

RANGES

SP2 DESCRIPTOR

SP1 DESCRIPTOR

SP/AL

MENU

UP

ARROW

DOWN

ARROW

ENTER

RESET

Home
Position Function

Sequences the display
through SET POINT and
ALARM settings
Allows access to the menus

Displays full scale
range of unit

Clears or resets an Alarm
(alarm set for manual reset)

Main Menu Function

Return to home
position

Return to home
position

Sequences through
menus

Sequences through
menus

Enter into SUB MENU

6

Sub Menu Function

Return to home position

Return to previous menu

Increments a value

Decrements a value

Changes a value or
setting. Press ENTER and
display will blink. Adjust
with UP or DOWN arrows.
Press ENTER to store.
Display will stop blinking.

Peak/Valley SUB 
MENU resets display to
present value.