Dwyer E-57G Series 1950G Integral Explosion-Proof Pressure Switches Instruction Manual

June 4, 2024
Dwyer

E-57G Series 1950G Integral Explosion-Proof Pressure Switches
Instruction Manual

Specifications – Installation and Operating Instructions

Dwyer E 57G Series 1950G Integral Explosion-Proof Pressure
Switches

UL, CSA, FM Listed For
CL, I GR. A*, B, C, D – CL. II GR. E, F, G – CL. III
ATEX Compliant for
2813 II 2G Ex db IIB+H2 T6 Gb
EU-Type Certificate Number: DEMKO 19 ATEX 2216X
ATEX Standards:
EN IEC 60079-0, EN 60079-1
IECEx Certified for:
Ex db IIB+H2 T6 Gb (-40°C < Ta < +60°C)
IECEx Certificate of Conformity:
IECEx UL 19.0045X
IECEx Standards:
IEC 60079-0, IEC 60079-1
KCs Certified for
Ex d IIB+H2 T6
KCs Certificate of Conformity
20-KA4BO-0539X
PESO Reference No. P484406/1
Ex d IIB+H2 T6 Gb
UKCA Ex Compliant for
II 2G Ex db IIB+H2 T6 Gb
UKCA Ex Certificate
UL21UKEX2362X
UKCA Ex Standards
EN IEC 60079-0, EN 60079-1

The Series 1950G Explosion-Proof Switch combines the best features of the popular Series 1900 Pressure Switch with compact explosion-proof housing.

This unit is UL, CSA, and FM listed for use in Class I, Groups A*, B, C, D, Class II, Groups E, F, & G, and Class III atmospheres and Directive 2014/34/EU (ATEX) Compliant for 2813 II 2G Ex db IIB+H2 T6 Gb. IECEx certified Ex db IIB+H2 T6 Gb (-40°C < Ta < + 60°C) units are available. It is also totally rain-tight for outdoor installations.
Six models allow set-points from 0.07 to 20 in w.c. (1.78 mm to 508.0 mm w.c.).

Easy access to the SPDT relay for electrical hook-up is provided by removing the top plate of the aluminum housing. A captive screw allows the cover to swing aside while remaining attached to the unit. Adjustment to the set point of the switch can be made without disassembly of the housing. The unit is very compact, about half the weight and bulk of equivalent conventional explosion- proof switches.

Attention: Units with the “NA” suffix are not Directive 2014/34/EU (ATEX) compliant.
These units are not intended for use in potentially explosive atmospheres in the EU.
These units may be CE marked for other Directives of the EU.

SPECIFICATIONS

Service: Air and compatible combustible gases.
Wetted Materials: Contact factory.
Temperature Limits: 0 to 140°F (-17 to 60°C). Note: Set-point drift may occur with ambient temperature changes.
Pressure Limits: 45 in w.c. (11.2 kPa) continuous; 10 psig (68.95 kPa) surge.
Enclosure Rating: IP54, NEMA 3, 7, and 9.
Switch Type: 1 Form C relay (SPDT).
Electrical Rating: 10A, 120/240 VAC, 28 VDC. Resistive 50 mA, 125 VDC.
Power Requirements: 24 VDC ±10%. 120 or 240 VAC ±10% optional.
Electrical Connections: Internal terminal block.
Process Connections: 1/8˝ female NPT.
Mounting Orientation: Diaphragm in vertical position. Consult the factory for other position orientations.
Set Point Adjustment: Screw type on top of the housing.
Weight: 2 lb 15.7 oz (1.35 kg).

Note: References to ATEX apply to UKCA Ex.

MODEL 1950G SWITCHES:
OPERATING RANGES AND HEADBANDS

To order Specify
Model Number| Operating
Range
in w. c.| Approximate Dead Band
At Min.
Set Point| At Max.
Set Point
1950G-00-B-
1950G-0-B-

1950G-1-B-
1950G-5-B-

1950G-10-B-
1950G-20-B-
| 0.07 to 0.15
0.15 to 0.5
0.4 to 1.6
1.4 to 5.5
3.0 to 11.0
4.0 to 20.0| 0.04
0.06
0.11
0.4
0.9
1.2| 0.06
0.11
0.29
0.9
1.8
3.0
Specify either 24 for 24 VDC, 120 for 120 VAC, or 240 for 240 VAC when ordering. Example: 1950G-00- B-120
*Add “NA” suffix for models with UL, CSA, and FM approvals only. Example: 1950G-00-B-120-NA

Dwyer E 57G Series 1950G Integral Explosion-Proof Pressure Switches - Fig
1

INSTALLATION

  1. Select a location free from excess vibration and corrosive atmospheres where temperatures will be within the limits noted under Physical Data on page 1. The switch may be installed outdoors or in areas where the hazard of explosion exists. See page 1 for specific types of hazardous services.

  2. Mount standard switches with the diaphragm in a vertical plane and with switch lettering and nameplate in an upright position. Some switches are position sensitive and may not reset properly unless they are mounted with the diaphragm vertical.

  3. Connect the switch to the source of pressure, vacuum, or differential pressure. Metal tubing with 1/4˝ O.D. is recommended, but any tubing which will not restrict the airflow can be used. Connect to the two 1/8˝ female NPT pressure ports as noted below.
    A. Differential pressures – connect pipes or tubes from the source of greater pressure to the high-pressure port marked HIGH PRESS, and from the source of lower pressure to the low-pressure port marked LOW PRESS.
    B. Pressure only (above atmospheric pressure) – connect a tube from a source of pressure to a high-pressure port. The low-pressure port is left open to the atmosphere.
    C. Vacuum only (below atmospheric pressure) – connect a tube from the source of the vacuum to the low-pressure port. The high-pressure port is left open to the atmosphere.

  4. To make electrical connections, remove the three hex head screws from the cover, and after loosening the fourth captive screw, swing the cover aside. Electrical connections to the standard single pole, double throw relay, and AC supply voltage connections to the unit, are provided by means of terminals marked “COM”, “NO”, “NC”, “~” and “~”  (See Figure A). Electrical connections to the standard single pole, double throw relay, and DC supply voltage connections to the unit, are provided by means of terminals marked “COM”, “NO”, “NC”, “+” and “-” (See Figure B.). The normally open contacts close and the normally closed contacts open when pressure increases beyond the set point. Switch loads for standard models should not exceed the maximum specified current ratings as stated on page 1. For ATEX, IECEx compliance, cables and cable glands suitable for the temperature of at least 105°C shall be used. The cable entry device shall be of the certified flameproof type, suitable for the conditions of use, and be correctly installed. Refer to Certificate No.: IECEx UL 19.0045X for conditions of safe use for IECEx Compliant units.
    Switch capabilities decrease with an increase in ambient temperature, load inductance, or cycling rate.

For units supplied with both internal and external bonding terminals, the ground screw inside the housing must be used to ground the control. The internal bonding screw is for supplementary bonding when allowed or required by local code. When an external bonding conductor is required, the conductor must be wrapped a minimum of 180° about the external bonding screw. See below.

Dwyer E 57G Series 1950G Integral Explosion-Proof Pressure Switches - Fig
2

ADJUSTMENT

To change the setpoint:
A. Remove the plastic cap and turn the slotted Adjustment Screw at the top of the housing clockwise to raise the setpoint pressure and counter-clockwise to lower the setpoint.  After calibration, replace the plastic cap and re-check the setpoint.
B. The recommended procedure for calibrating or checking calibration is to use a “T” assembly with three rubber tubing leads, all as short as possible and the entire assembly offering minimum flow restriction. Run one lead to the pressure switch, another to a manometer of known accuracy and appropriate range, and apply pressure through the third tube. Make the final approach to the setpoint very slowly. Note that the manometer and pressure switch will have different response times due to different internal volumes,  lengths of tubing, fluid drainage, etc. Be certain the switch is checked in the position it will assume in use, (i.e. with the diaphragm in a vertical plane) and switch lettering and Dwyer nameplate in an upright position.
C. For highly critical applications check the setpoint adjustment and if necessary, reset it as noted in step A.

MAINTENANCE

The moving parts of these switches need no maintenance or lubrication. The only adjustment is that of the setpoint. Care should be taken to keep the switch reasonably clean.  Periodically the vent drain plug should be rotated and then returned to its original position. This will dislodge deposits that could accumulate in applications where there is excessive condensation within the switch. Repairs are to be conducted by Dwyer Instruments, LLC. Cover bolts are Class 10.9 35 mm long.

DWYER INSTRUMENTS, LLC
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.

Phone:219-879-8000
Fax:219-872-9057

www.dwyer-inst.com
e-mail: info@dwyermail.com

References

Read User Manual Online (PDF format)

Read User Manual Online (PDF format)  >>

Download This Manual (PDF format)

Download this manual  >>

Dwyer User Manuals

Related Manuals