Omega Products DPG1000DAR Installation Manual

Digital Pressure Gauges

DPG1000DAR Series, Low Voltage AC/DC Powered
with Dual Alarm Relays and 4 to 20 mA Output

INSTRUCTION

MANUAL

M3363/1001

Installation Precautions

Tighten/remove with wrench on hex fitting only. Do not attempt to rotate
gauge by turning housing. Use fittings appropriate for the pressure range of
the gauge. Do not apply vacuum to gauges not designed for vacuum
operation. NEVER insert objects into the gauge port or blow out with
compressed air.Permanent damage not covered by warranty will result.

Electrical Connection

NEVER connect the gauge power wires directly to 115 VAC or permanent

damage not covered by warranty will result.
The two-conductor cable at the gauge rear with the RED and BLACK leads

is for the gauge power supply. Connect to 8 to 24 VAC, 50/60Hz or 9 to 32
VDC.The gauge will operate on either AC or DC power and there is no need
to observe polarity. An unregulated power supply can be used. The supply
voltage, when within the stated ranges, has negligible effect on the gauge
calibration. Operation below 9 VDC or 8 VAC RMS may cause erratic or
erroneous readings or output.

The gauge is powered on whenever a supply voltage is applied. Warm-up
time is negligible.In normal operation the system pressure is displayed.

The color code for the 6-conductor alarm relay output cable is as follows.

SETPOINT 1 SETPOINT 2

Normally Closed (NC) BLACK Normally Closed (NC) GREEN
Common (C) RED Common (C) BROWN
Normally Open (NO) WHITE Normally Open (NO) BLUE

The shield (drain) wire is generally not needed for 4-20 mA current loops
unless long cable lengths are used in electrically noisy environments.

Operation

The gauge is on whenever a supply voltage is applied.Warm-up time for full
accuracy is negligible.In normal operation, the system pressure is displayed
on the gauge LCD.The circuitr y also compares the system pressure to two
independent setpoint levels;Setpoint 1 and Setpoint 2. These setpoint levels
may be viewed by pressing either the SP1 or SP2 buttons. Operation of the
alarm outputs is not affected by pressing SP1 or SP2.

Alarm status is easily seen on the two alarm indicator LEDs in the corner of
the SP1 and SP2 buttons. A GREEN indication is a normal or non-alar m
condition; RED is an abnormal or alarm condition.

In the standard HI/LO configuration, SP1 is configured as a HI alarm and will
provide a RED alarm indication when the system pressure exceeds the
setpoint. SP2, the LO alarm will provide a RED alar m indication when the
system pressure falls below the setpoint.

Test Button

For system setup, testing, and troubleshooting, the TEST button is provided.
The alarm outputs and the current loop may be “exercised” on demand
without the need to vary the system pressure to test devices, annunciators,
etc. connected to these outputs.

When the TEST button is pressed, the alarm relays are toggled to the
opposite state, and the 4-20 mA output is set to the “test” level, which is
indicated on the display.

The test level of the 4-20 mA output is determined by the setting of the top­accessible TEST potentiometer. To set the “test calibration” level, lift the top
calibration label and locate the “TEST” potentiometer. While pressing the
TEST button, adjust the display to the desired pressure reading that will be
output as a 4-20 mA signal. For example, on a 0 to 100 psi gauge, setting
the test level to 50.0 will give a 12 mA output whenever the TEST button is
depressed.

Setting Alarms

To access alarm SP1 and SP2 controls, lift the calibration label on the top of
unit and locate the proper potentiometer as indicated by the gauge rear
label.This label can be reused many times.

Pressing SP1 or SP2 will switch the display to show and allow adjusting of
the corresponding alarm setpoint.

To adjust alarm Setpoint 1, press and hold the SP1 button.When holding the
SP1 button, the display will show the current setting for Setpoint 1. Turn the
top-accessible Setpoint 1 control. Repeat the procedure by pressing and
holding the SP2 button to adjust Setpoint 2.

It is allowable to set the LO alarm to a higher pressure than the HI alarm.
Normal (Failsafe) vs. Reverse Action - Alarm configuration is set at the

factory at time of manufacture. Standard is a Normal (Failsafe) action HI/LO
configuration where SP1 is the HI alarm and SP2 is the LO alarm. Gauges
with HI/HI, LO/LO and reverse action relay configurations are also available.

With the Normal or Failsafe configuration, the alarm output relays will be
CLOSED (relay energized) for a clear or non-alarm condition and OPEN
(relay not energized) for an alarm condition. This is primarily for users who
desire an alarm condition should the gauge lose power. “Normally closed”
and “normally open” designations refer to standard relay terminology; i.e.,
the relay contact status with the relay coil not energized.

With the Normal (Failsafe) configuration, when in a green or non-alarm
condition, the relay will be energized so that continuity can be expected
between the common and normally open leads. In a red or alarm condition,
the relay will be open (not energized), so that continuity can be expected
between the common and normally closed leads.

With the Reverse acting alarm configuration, the relays will be open (not
energized) in the non-alarm condition and closed for the alarm condition. In
this case, continuity can be expected from common to normally closed in the
green (non-alarm) condition and from common to normally open in the red
(alarm) condition. This configuration can be used if a non-alarm condition is
desired when the gauge power is shut off.

Alarm Deadband - The alar m circuit setpoints have built-in deadbands, also
known as hysteresis, of 1% of span as standard.This means, for example,
the deadband is approximately 1 psi in a 0 to 100 psi gauge.

This deadband serves to eliminate output oscillation or “chatter” of the
alarms due to minor fluctuations in pressure. If, for example, the system
pressure in a 0-100 psi system is 40.0 psi, and Setpoint 1 is set to 50.0 psi
(HI alarm), the alarm indication will trip if the pressure exceeds 50.0 psi.
After the HI alarm has tripped, pressing the SP1 button will show that the
alarm indication will “release” at 1 psi lower (approximately 49 psi).
Deadband is set at the factory to 1% but other deadbands can be configured
at the factory where the application requires.

Contact Rating and Protection - The contacts of the alarm relays are rated
at 1A/24VDC or 0.5A/115VAC maximum with non-inductive loads. Using
mechanical relay contacts above their rating, or with large inductive loads,
will shorten their useful life. In circuits other than low-level switching or pilot
duty, the user should consider whether external contact protection such as
snubber networks or arc suppression networks are required to protect the
contacts. When switching higher electrical loads, the alarm relay should be
used to drive an external contactor or solid state relay of sufficient capacity.

In addition, no internal fusing is included in the gauges. The circuit external
to the gauge alarm outputs should be fused by the user in applications
where good design practice dictates.

1

/4" NPT

2.88"

3.38"

0.75"

1.65"

Turn at

hex

fitting

only!

0.75"

Two 3 ft long, 4­conductor & 6
conductor
22 AWG shielded
cables

SPECIFICATIONS

Ranges & Resolution

30.0 inHg vacuum, ±15.00, 3.00, 5.00, 15.00 psig

30.0, 100.0, 199.9, 300, 500, 1000, 3000, 5000 psig
Absolute reference:15.00, 100.0 psia

Optional Units

Most engineering units such as kPa, atm, bar,
mbar, inHg, mmHg, inH2O, ftH2O, torr, kg/cm2,
cmH

2

O, oz/in

2

Display (type, size, update rate)

Ranges up to 1999: 3

1

/

2 digit LCD,

1

/

2" digit height

3000 & 5000 psi ranges: 4 digit LCD, 0.4" H digits
3 readings per second nominal display update

Accuracy (linearity, hysteresis, repeatability)

±0.25% of full scale or better, ±1 least significant
digit

Temperature Stability(rel. to 77°F or 25°C)

±1% FS for offset & span, 32 to 158°F (0 to 70°C)
typical
±2% FS for offset & span, 32 to 158°F (0 to 70°C)
typical for 3 and 5 psi ranges

Alarm Deadbands (hysteresis)

1% of of full scale

Alarm Outputs

Dual form C (SPDT) relay contacts
Individual Setpoint 1 and Setpoint 2 settings via
top-accessible multiturn potentiometers
HI/LO alarm configuration standard
Relay contacts rated 1A/24VDC, 0.5A/115VAC
maximum, non-inductive

Alarm Indicators

Bicolor (red/green) LEDs on front panel

Alarm Response Time

100 milliseconds typical

Test Function

Front panel TEST button toggles SP1 and SP2
alarm status and 4-20 mA output to test level,
independent of pressure input to allow testing of
system operation.

Retransmission Output

4-20 mA DC true analog output, 50 milliseconds
typical response time.Output drive (compliance)
determined by power source.

Power

DC 9 to 32 VDC, or AC 8 to 24VAC 50-60Hz

1.0 watt max.power consumption

Storage Temp:–40 to 203°F (–40 to 95°C)
Operating Temp:–4 to 185°F (–20 to 85°C)
Compensated Temp:32 to 158°F (0 to 70°C)
Weight (approximate)

Gauge: 9 ounces, shipping weight: 1 pound

Housing

Extruded aluminum case, light gray epo xy powder
coated
Black polycarbonate cover, front and rear gaskets

Electrical Connection

3 ft long, 4-conductor 22AWG cable for power
and 4-20 mA output.
3 ft long, 6-conductor 22AWG alarm relay cable

Pressure/Vacuum Connection & Material

1

/

4

" NPT male.All wetted parts are 316SS

Overpressure & Burst

5000 psig for 3000 psig range
7500 psig for 5000 psig range
All others 2x rated pressure minimum
Burst: 4x rated pressure minimum or 10,000 psi,
whichever is less

Using the 4-20 mA Output

The 4-20 mA output is driven by the transducer rather than the display and
thus is a true analog output.The output is filtered to improve noise immunity
and thus has a response time of about 50 msec.

The power supply (–) lead is tied to the 4-20 mA output ground. Therefore
the DC supply (–) lead should be considered common with regard to the 4­20 mA output (–) or ground connection.

Be sure to observe the output compliance (voltage drive) capabilities of the
gauge. The compliance, and therefore the maximum loop resistance the
output can drive, is a function of the supply voltage to the gauge. Consult
the graph below for maximum loop resistance vs. supply voltage.Too large a
loop resistance will cause the gauge output to “limit” or saturate before
reaching its full 20 mA output.

Calibration

These gauges are factory calibrated and normally do not require
recalibration before being put into service. If calibration is required, lift
calibration label on the top of unit to access the Zero and Span controls.this
label is designed to be reused many times.

For GAUGE reference units the setting of the Zero control is correct when
the gauge reads zero, with the “–” sign occasionally flashing, when the
pressure port is open to the ambient. Zero calibration must be done before
span calibration is attempted. Since the calibration potentiometers are non-

interactive, gauge reference units may be rezeroed without affecting the
span.

Span calibration should only be done when a pressure reference of known
accuracy is available. The calibration equipment accuracy should be better
than 4 times the accuracy of the gauge. Zero calibration must be done
before span calibration. Record readings at three to five points over the
range of gauge and adjust span control to minimize error and meet
specifications.

Calibration of ABSOLUTE reference units is more difficult and is not
recommended in the field, unless the user has access to equipment
required to calibrate absolute-reference units, such as vacuum generation
and atmospheric pressure measurement equipment.

Gauges can be returned to Omega Engineering for recalibration. NIST
traceability is available.

The DPG1000DAR has internal controls that adjust the “agreement”
between the displayed value and the 4-20 mA loop current. These are
carefully set at the factory and should not normally be adjusted. Should the
user feel this adjustment is necessary, the display zero/span must be
accurately set first. Then, after removing the rear cover, the “loop zero” and
“loop span” controls may be trimmed for 4.00 mA of loop current at the low
end of the range, and 20.00 mA at the high end of the range, respectively.
Accurate pressure generation and measurement, and current measurement
equipment are required to successfully complete this calibration.

OMEGA Engineering Inc./Made in USA

TEST

SP1 SP2

1400

1200

1000

800

600

400

200

0

Max Loop Resistance (Ohms)

8 121620242832

Supply V oltage

Voltage Compliance for 4-20 mA Output

PSIG

DC

AC

Gauge power supply

9-32 VDC

or

8-24 VAC 50/60 Hz

(–)BLACK

(+)RED

(+)WHITE

(–)GREEN

Remote device

Optional

shield

connection

Zero SP2

Span

Test

SP1

See "Electrical Connections"

for relay wiring