1.0 GENERAL INFORMATION

Every Model 809 has been tested and calibrated before shipment.

Gems Sensors 809 pressure transducers sense gauge pressure and convert this

pressure difference to a proportional high level analog output. Three standard

output and excitation versions are offered:

Excitation Output

9 to 28 VDC 4 to 20 mA - (Must Observe Polarity)

9 to 30 VDC 0.5 to 5.5 VDC - (Reverse excitation protection)

4.9 to 8.1 VDC 0.5 to 4.5 VDC - (No reverse wire protection)

2.0 MECHANICAL INSTALLATION

2.1 Media Compatibility

Model 809 transducers are designed to be used with any gases or liquids

compatible with 17-4 PH Stainless Steel.

2.2 Environment

The operating temperature limits of the 809 are -40° to +185°F (-40 to +85°C).

The compensated temperature range is -4 to +176°F (-20 to +80°C).

2.3 Pressure Fittings

Typically, standard pipe fittings and procedures should be used. However, for

pressure ranges in excess of 500 psig, we suggest the use of a sealant such as

Loctite Hydraulic Sealant. Excessive torquing of metal fittings may cause a

slight zero shift. The use of plastic fittings typically results in no noticeable zero

shift. Torquing does not appreciably affect linearity or sensitivity.

2.4 Tube Stub Welding Instructions

Standard welding practices should be followed. Caution must be taken to

protect the sensor against current paths that could damage the circuit board.

Apply a heat sink between the weld zone and the sensor that is large enough

to protect the sensor from overheating. Failure to use a heat sink may damage

the housing seal or circuit board.

2.5 Venting

Because the reference pressure in a sealed gage transducer will vary due to

changes in temperature and will affect overall accuracy (especially in units of

less than 500 psig range), all 809 Series transducers are available as vented or

sealed to atmosphere.

Vented units are ordered as PSIG range units. Sealed units are ordered as PSIS

range units. The 809 PSIG transducers are vented through the cable.

Hirschmann PSIG transducers are vented through the connector. Packard

PSIG units are vented through a porous filter plug supplied on the unit.

3.0 ELECTRICAL INSTALLATION

The Model 809 is available in four electrical terminations:

2 foot Cable Hirschmann Connector

Packard Connector Conduit Adapter, 1/2 inch

Gems Sensors 809 Series

Pressure Transducer

Instruction Bulletin No. 203022

SS2114 Rev. A 01/03

RETURN POLICY

Returns are accepted on stock items up to 30 days from date of order.

You must contact our Returns Department for a Return Authorization

(RA) number. Return the goods - freight prepaid - in the original

container and include original packing slip. C. O. D. returns are not

accepted. Gems reserves the right to apply restocking charges.

Tel: 860-793-4357

Fax: 860-793-4563

Gems Sensors

One Cowles Road

Plainville, CT 06062-1198

Toll-Free: 1-800-378-1600

● Gems products must be maintained and installed

in strict accordance with the National Electrical

Code and the applicable Gems Product Instruction

Bulletin that covers installation, operating and

proper maintenance. Failure to observe this

information may result in serious injury or

damages.

● Please adhere to the pressure and temperature

limitations shown throughout this bulletin. These

limitations must not be exceeded. These pressures

and temperatures take into consideration possible

system surge pressures/temperatures and their

frequencies.

Important Points

● Selection of materials for compatibility with the

media is critical to the life and operation of Gems

products. Take care in the proper selection of

materials of construction, testing is required.

● Our sensors have been designed to resist shock and

vibration. However, shock and vibration should be

minimized.

● Our sensors must not be field-repaired.

● Physical damage sustained by product may render it

unserviceable.

3.2 Current Output Units

The Model 809 (current output) transducer is a true 2-wire, 4-20 mA current

output device and delivers rated current into any external load of 0-800 ohms.

The 4-20 mA units are designed to have current flow in one direction only -

PLEASE OBSERVE POLARITY. We suggest that the electrical cable shield be

connected to the system’s loop circuit ground to improve electrical noise

rejection. The electrical connection is as follows:

Red + Excitation

Black - Excitation

Monitor or

Control

Device

Green

+ Out

White

- Out

Shield

3.3 Hirschmann or Packard Connectors - Voltage and Current Output

If the unit is provided with a Hirschmann or a Packard Connector, pin number

designations are as follows:

3.1 Voltage Output Units

The Model 809 voltage output is a 3-wire circuit. If the 809 is supplied with 2 feet of

cable, the electrical connection is as follows:

Red =

+ Excitation; connect to appropriate power supply.

Green =

+ Output; connect to controls or monitor.

Black =

Common; connect to return of power supply.

White =

- Output; connect to controls or monitor.

Shielding =

Connect to system or earth ground.

-Out White

+Out Green

Hirschmann Connector

3-Pin Packard Connector

Top View: 3-Pin Packard Connector

Type: P2S Series 150

Voltage Output

Pin # Function

1+ Excitation

(connect to appropriate power supply)

3+ Output (connect to controls or monitor)

2Common (connect to return of power supply)

Top View: Hirschmann Connector

Type: G4A1M#931807-106

Pin # Function

1Positive

2Negative

Current Output

Voltage Output

Pin # Function

B + Excitation (connect to appropriate power supply)

C + Output (connect to controls or monitor)

A Common (connect to return of power supply)

Pin # Function

BPositive

ANegative

Current Output

The 809 has a 2-wire cable, where red is positive and black is negative.

CAUTION: Reverse excitation will not cause damage to unit unless voltage

applied is above 50 VDC. However, unit will not function if reverse wired.

Model 809

Gems Transducer

(4-20 mA)

Power

Supply

Load

(Monitor)

Red

Black

CAUTION: Unit is reverse excitation protected. However, do not

apply power to output lead as this could cause permanent damage.

3.4 Conduit Adapter Electrical Termination - Voltage and Current

Output Units

If the unit is provided with the conduit adapter version, terminal designations

are as follows:

Conduit Adapter Version

(Voltage and Current Output Units)

For current (4-20 mA)

output, use + and -

terminals

For voltage output, use

COM, OUT and EXC

terminals

1. Connect the pressure port to the system.

2. Install a 1/2’’ conduit fitting into the 809 top cover, and fasten the retaining nut.

3. Feed wires from a flexible conduit through the 809 top cover, fasten the wires to terminals.

4. Screw on the Model 809 top cover.

5. Fit conduit into conduit fitting, and tighten conduit watertight strain relief.

CONDUIT FITTING INSTALLATION INSTRUCTIONS

4-Pin Packard Connector

Gems does not supply the mating connectors as a standard. They can be ordered

separately. Consult Factory

Pin # Function

APositive

BNegative

Top View: 4-Pin Packard Connector

Type: Metri-Pack 150

Current Output

Voltage Output

Pin # Function

A + Excitation (connect to appropriate power supply)

C + Output (connect to controls or monitor)

B Common (connect to return of power supply)

D (Not Used)

Vent

3.6 EMC Certification

This product complies with EN61326 Electrical Equipment for Measurement, Control and

Laboratory use – EMC Requirements for Minimum Requirements and Industrial Locations.

Special caution should be taken to meet Standard EN61000-4-5: 1995 Surge Immunity if

any of the following conditions apply to the installation: The product is installed outside;

all or any part of the cable is exposed to the outside; the cable is greater than 30 meters in

length. In order to meet the Surge Immunity requirements, the following conditions must

be followed during installation:

1. Shielded cable must be used, and the shield must be tied to earth ground (not power supply

ground) on at least one end of the cable shield/drain wire. The shield must be maintained all

the way from sensor to the power supply.

2. If unshielded cable is used, an earth grounded metal conduit fitting can be used to replace the

shielded cable.

3. For a sensor with a metal body or enclosure, the body/enclosure must be grounded to earth. If

a protective metal housing is used, the metal housing should be grounded to earth

4. If a protective plastic housing is used, the housing must be able to withstand at least

2 KV from the housing to earth ground, without damaging the circuit.

3.5 Conduit Fitting Installation