Dwyer Series 1950G Integral Explosion-Proof Pressure Switches Instructions
- June 4, 2024
- Dwyer
Table of Contents
Dwyer Series 1950G Integral Explosion-Proof Pressure Switches
OVERVIEW
-
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
Ex II 2G Ex db IIB+H2 T6 Gb
UKCA Ex Certificate
UL21UKEX2362X
UKCA Ex Standards
EN IEC 60079-0, EN 60079-1
ABOUT
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, 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 factory for other position orientations.
- Set Point Adjustment: Screw type on top of housing.
- Weight: 2 lb 15.7 oz (1.35 kg).
Note: References to ATEX apply to UKCA Ex.
MODEL 1950G SWITCHES
MODEL 1950G SWITCHES:
OPERATING RANGES AND DEAD BANDS
**To order Specify Model Number***
|
Operating Range
in w. c.
| Approximate Dead
Band
At Min.
Set Point
| At Max.
Set Point
1950G-00- B-| 0.07 to 0.15| 0.04| 0.06
1950G-0- B-| 0.15 to 0.5| 0.06| 0.11
1950G-1- B-| 0.4 to 1.6| 0.11| 0.29
1950G-5- B-| 1.4 to 5.5| 0.4| 0.9
1950G-10- B-| 3.0 to 11.0| 0.9| 1.8
1950G-20- B-| 4.0 to 20.0| 1.2| 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
Dimensions
INSTALLATION
- Select a location free from excess vibration and corrosive atmospheres where temperatures will be within the limits noted under Physical Data on page 1. Switch may be installed outdoors or in areas where the hazard of explosion exists. See page 1 for specific types of hazardous services.
- 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.
- Connect the switch to 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 source of greater pressure to high-pressure port marked HIGH PRESS, and from source of lower pressure to low-pressure port marked LOW PRESS.
- B. Pressure only (above atmospheric pressure) – connect tube from source of pressure to high-pressure port. The low-pressure port is left open to atmosphere.
- C. Vacuum only (below atmospheric pressure) – connect tube from source of vacuum to low-pressure port. The high-pressure port is left open to atmosphere.
- 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 setpoint. 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 temperature of at least 105°C shall be used. The cable entry device shall be of 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 external bonding conductor is required, conductor must be wrapped a minimum of 180° about the external bonding screw. See below.
ADJUSTMENT
To change the setpoint:
- 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.
- 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 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.
- 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 then returned to its original position. This will dislodge deposits that could accumulate in applications where there is excessive condensation within the switch. Repairs 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)
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