1 weatherproof . PRESSURE SWITCHES FLAMEPROOF . S20 / 920 SERIES. DIAPHRAGM-SEALED PISTON SENSOR HIGH STATIC PRESSURE . FIELD ADJUSTABLE SETPOINT RUGGED DESIGN. MODEL 924 IN GH MODEL S21 IN GM MODEL S24 IN GK. weatherproof ENCLOSURE weatherproof ENCLOSURE weatherproof ENCLOSURE. Rugged in construction, supreme in performance the S20 The sensing element consists of a time-proven diaphragm and 920 series PRESSURE SWITCHES are designed as cost sealed piston affording high integrity, reliable switching and effective solutions to meet a variety of applications in the oil, a very high overload protection. Variety of combinations in gas, power, steel, Nuclear energy and petrochemical features are available to make it versatile. industries. GENERAL SPECIFICATIONS. Enclosure Repeatability 1 % FSR (Note 4). GM Aluminium PRESSURE die cast Scale Accuracy 5 % FSR (for GH only) (Note 6). weatherproof to IP:66 Mounting Direct or Wall GA4 304SS investment cast weather - Max. Working Pr. Refer tables A' & B'.
2 proof to IP:66 Max. Working Temp. 20 to + 80 C for all ranges except GA6 316SS investment cast weather - 20 to + 60 C for ranges U7, V7, proof to IP:66 W7 & Y4 (Note 14). GK Aluminium die cast, weatherproof Switching to IP:66 and FLAMEPROOF to , Element Instrument quality snap-acting IIB or IIC (Note 1) SPDT microswitch GH Aluminium PRESSURE die cast Differential Fixed; for values refer tables A' & B'. weatherproof to IP:66 Connection Ranges ( )1 to 700 bar -several std. ranges. Process 1/4" NPTF Std., 1/2" NPTF on request Refer Table 1 others through Adaptor Sensor 316L SS Diaphragm-sealed piston Electrical std. Monel optional GM / GA4 / GA6 3/4" ETF std; 1/2" NPTF optional. Dual Wetted Parts entry on request. Diaphragm Housing 304 SS Standard GK 1/2" NPTF std. Dual entry on request. 316 SS & Monel Optional GH 3/4" ET Nylon cable gland std. Diaphragm Seals Nitrile Std ;. EPDM /Teflon / Viton Optional Conformity Generally to BS : 6134 : 1991. Monel is a registered trademark of The International Nickel Company, Inc Viton is a registered trademark of DuPont Dow Elastomers ORDERING MATRIX.
3 ENCLOSURE Table 1 : RANGE CODE & AVAILABILITY. Aluminium PRESSURE die cast weatherproof RANGE RANGE MODELS. to IP:66. GM. CODE (in bar) S21 S24 921 924. 304 SS investment cast weatherproof to IP:66 with overall size as style GM. G3 ( )1 to (+) . for aggressive atmospheres ideal for DB to . offshore. GA4 DC to 316 SS investment cast weatherproof DE 1 to 6. to IP:66 with overall size as style GM EA to 10. for aggressive atmospheres ideal for EB to 16. offshore. GA6. EC 4 to 25. Aluminium die cast FLAMEPROOF cum ED 10 to 40. weatherproof . CIMFR approved to IIB & IIC of IS/IEC 60079 1:2007 for flame- FA 10 to 100. proofness and IP:66 for U7 7 to 160 . Aluminium PRESSURE die cast compact V7 25 to 250 . housing. weatherproof IP:66. GH W7 50 to 400 . MODEL Y4 100 to 700 . S20 Series (available in Style GM, GA4, GA6 & GK. enclosures only) Table 2 : SWITCH CODE RATING & AVAILABILITY (Note 8). Fixed differential with maximum working DC RATING IN AMPS. AVAILABILI- SWIT- TY. pressures upto 155 bar as per table A'.
4 S21. CH AC OF SPDT. RESISTIVE INDUCTIVE. Fixed differential with maximum working CODE RATING AND. (SPDT) DPDT IN. pressures upto 1000 bar as per table B'. S24 220V 110V 24V 220V 110V 24V. MODELS. 920 Series 15A 250 / S21, S24, D (available in Style GH enclosure only) 125V 921 & 924. 10A 250 / S21, S24, Fixed differential with maximum working H 125V 921 & 924. pressures upto155 bar as per table A'. 921 15A 250 / S21, S24, 3 125V 921 & 924. Fixed differential with maximum working S21, S24, pressures upto1000 bar as per table B'. 924 4 1A 125V 921 & 924. 5A 250 / S21, S24, MATERIALS OF WETTED PARTS 5 125V 921 & 924. 316L SS diaphragm, Nitrile O' ring and S21, S24, 6 125V 304 SS wetted parts. 04 921 & 924. S21, S24, 316L SS diaphragm, Nitrile O' ring and 7 921 & 924. 316 SS wetted parts. 02 5A 250 / S21, S24, 8 125V 921 & 924. 316L SS diaphragm, Nitrile O' ring and 5A 250V / S21, S24, 316 SS wetted parts. 0L J 125V 921 & 924. 1A 250V / S21, S24, 316L SS diaphragm, Viton O' ring and 316 SS K 125V 921 & 924.
5 Wetted parts for NACE MR 01 75. 0N 5A 250 / S21, S24, S Monel diaphragm, Nitrile O' ring and 125V 921 & 924. S21, S24, 316 SS wetted parts. M2 R 250V 921 & 924. Monel diaphragm, Viton O' ring and Monel Codes D & H General purpose Code 8 Environmentally sealed wetted parts for NACE MR 01 75. 0M AC & DC rating. switch with Silver contact. Code 3 General purpose only Code J Hermetically sealed, inert 316L SS diaphragm and 316 SS wetted parts AC rating. gas filled with Silver contact. W elded construction. W2 Code 4 With Gold alloy contact. Code K Hermetically sealed, inert Code 5 For General purpose with RANGE CODE : Refer Table 1 good DC rating. gas filled with Gold plated contact. Code 6 With Gold alloy contact Code S IP:67 sealed microswitch SWITCH CODE AND RATING : Refer Table 2 with silver Alloy contact. (Low Rating). ELECTRICAL ENTRY : Refer Table 3 Code 7 Environmentally sealed Code R IP:67 sealed microswitch switch with Gold plated contact. with gold plated contact For reduced risk against leakage under extreme or exceptional conditions the diaphragm is welded to For DPDT, change switch code to DD , 33 , etc.
6 , while ordering the PRESSURE housings eliminating the 'O' ring. Not Available Not Recommended Table 3 : ELECTRICAL ENTRY. NOTES. Single Entry Dual Entry Size GM/GA GK GH GM/GA GK GH 1. & IIB of IS:2148 is equivalent to NEC , & D. of IS:2148 is equivalent to NEC , , & B. 3/4" ETF A --- --- M --- M. 2. Style GM / GA4 / GA6 / GH is weatherproof only if all entries 1/2" NPTF B B B N N N and joint faces are properly sealed. Style GK is weatherproof 3/4" NPTF C --- C O --- O only if cover O' ring is retained in position and FLAMEPROOF only if proper FLP cable gland is used. It is recommended to M20 D D D P P P. procure cable glands along with GK instruments to avoid M16 E --- E Q --- Q neglect of it while installation. Through Connector Plug and Socket in MS 3. Intrinsic Safety (Exi) PRESSURE SWITCHES are classified as simple apparatus as they neither generate nor store energy. 3 pin plug 2 --- 2 --- --- --- Hence PRESSURE SWITCHES in weatherproof (GM / GA4 / GA6). 7 pin plug 3 --- 3 --- --- --- enclosures also may be used in intrinsically safe systems without certification provided the power source is certified 9 pin plug 4 --- 4 --- --- --- IS.
7 Bec aus e of the low voltages and c urrents it is Cable gland available on request. recommended to use gold contact and / or sealed contacts. Through adaptor except for GK housing. 4. Accuracy & Repeatability are not different for all blind PRESSURE SWITCHES . A shift of 2% may be observed in setpoint when PRESSURE falls from full static PRESSURE . Settings will also shift with varying temperature. 5. The instrument is calibrated in the mounting position depicted SWITCHING DIFFERENTIAL DATA in the drawing. Mounting in any other direction will cause a minor range shift, especially in low and compound ranges. TABLE A Ranges above 1 bar will not experience this shift. 6. A PRESSURE switch is a switching device and not a measuring On off Differentials in bar instrument eventhough it has a scale to assist setting in Range Range S21 / 921. MWP GH only. For this reason, Test Certificates will not contain Code (bar) (bar) individual ON-OFF switching values at different scale readings. 3/D/6 4 5 J/K 7/8/S Maximum differential obtained alone will be declared, besides G3 1 to 15 other specifications.
8 DB to 7. Select working range of the instrument such that the set value lies in the mid 35% of the range , between 35%. DC to 27 and 70% of range span. DE 1 to 8. For switching differential values please refer respective EA to 10 Differential Table. Switching differentials furnished are nominal 70 values under test conditions at mid-scale and will vary with EB to 16 range settings and operating conditions. EC 4 to 25 110 9. On and off settings should not exceed the upper or lower ED 10 to 40 range value. FA 10 to 100 155 10. DPDT action is achieved by two SPDT SWITCHES synchronised to practical limits , 2% of FSR. 11. Contact life of microswitches are 5 105 switching cycles Since the force required to operate the microswitches for nominal load. To quench DC sparks, use diode in parallel is higher in DPDT arrangement, for DPDT switching apply with inductance, ensuring polarity. A R C' network is also a multiplication factor of on the differential values recommended with R' value in Ohms equal to coil resistance with SPDT arrangement.
9 The above stated differentials and C' value in micro Farads equal to holding current in are at midscale. It would be twice at maximum range Amps. and half at minimum range. 12. All models of S20 and 920 series PRESSURE SWITCHES can withstand full vacuum. TABLE B 13. Ambient temperature range: All models are suitable for operating within a range of ambient temperature from ( ) 10 C. On off Differentials in bar to (+) 60 C provided the Process does not freeze within this Range Range MWP range. Below 0 C, precautions should be taken in humid Code (bar) S24 / 924 (bar) atmospheres to prevent frost formation inside the instrument 3/D/6 4 5 J/K 7/8/S from jamming the mechanism. Occasional excursions beyond this range are possible but accuracy might be impaired. The DC to microswitch is the limiting factor which should never exceed DE to the limits ( ) 25 C to (+) 80 C. 14. Fluid Temperature: A PRESSURE switch when connected to EA to 10 the Process is not subjected to through flow and therefore EB to 16 600 is not fully exposed to the fluid temperature.
10 Use of adequate length of impulse piping will greatly reduce excessive heating EC 4 to 25 of the sensing element. For , connection of cm of 12 mm dia impulse piping will reduce water temperature of ED 10 to 40 100 C to 65 C at an ambient temperature of 50 C. Ask factory FA 10 to 100 for piping nomogram #441184 4 for different temperatures. 15. Ensure that impulse pipework applies no stress on sensing U7 7 to 160 element housing and use spanners to hold PRESSURE port /. V7 25 to 250 housing when connections are made. 1000 16. Accuracy figures are exclusive of test equipment W7 50 to 400 tolerance on the claimed values. Y4 100 to 700 17. All performance data are guaranteed to 5%. MOUNTING DIMENSIONS. GH' Enclosure GH' Enclosure with External Terminal Housing 115 115. 104 8 36 44 104. 19 36. 24 28. 3/4" ET Nylon 81 90 81 90. 3/4" ET Nylon Cable Gland Cable Gland Fixing Holes 4 Nos. Terminal Housing Optional : Clamps 35~51 Fixing Holes 35~51. for Panel Mounting 4 Nos. Optional : Clamps 1/4" NPT(F) 35 23 for Panel Mounting 1/4" NPT(F) 35.