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GENERAL
The unit is manufactured, checked and supplied in
accordance with our published specification, and when
installed and used in normal or prescribed applications,
with the lid in place and within the parameters set for
mechanical and electrical performance, will not cause
danger or hazard to life or limb.
HEALTH AND SAFETY AT WORK ACT 1974
WARNINGS
1. THE USERS ATTENTION IS DRAWN TO THE
FACT THAT, WHEN THE UNIT IS "LIVE" WITH
RESPECT TO ELECTRICAL OR PRESSURE SUPPLIES,
A HAZARD MAY EXIST IF THE UNIT IS OPENED OR
DISMANTLED.
2. UNITS MUST BE SELECTED AND INSTALLED BY
SUITABLY TRAINED AND QUALIFIED PERSONNEL IN
ACCORDANCE WITH APPROPRIATE CODES OF
PRACTICE SO THAT THE POSSIBILITY OF FAILURE
RESULTING IN INJURY OR DAMAGE CAUSED BY
MISUSE OR MISAPPLICATION IS AVOIDED.
3. TYPE W AND A ENCLOSURES HAVE A SAFETY
BLOW-OUT DISC FITTED IN THE REAR OF THE
ENCLOSURE TO PREVENT DANGEROUS
PRESSURISATION OCCURRING IN THE EVENT OF A
SEAL FAILURE. THIS MUST NOT BE OBSTRUCTED
DURING INSTALLATION. LEAVE AT LEAST 6 mm
CLEARANCE BETWEEN THE BACK FACE OF THE
ENCLOSURE AND THE MOUNTING SURFACE. DO
NOT REMOVE OR REPLACE WITH ANY OTHER
DEVICE NOT APPROVED BY DELTA CONTROLS.
DO NOT REMOVE AND REFIT BACK PLATE SO AS TO
OBSTRUCT THE BLOW-OUT DISC.
CAUTIONS
1. Maximum single-ended or out of balance
pressure.
Ranges B2 = 500 mbar
Range B3, C6 = 1 bar
Ranges E1, E8, G5 J0 = 15 bar
2. Ranges up to C6 are only suitable for dry
gaseous mediums. Impulse lines should be
sized and installed to avoid condensation build
up affecting accuracy.
OPERATING PRINCIPLES
A diaphragm is used to sense the difference between two
pressures applied to either side of the diaphragm. The
diaphragm transmits a force proportional to the applied
pressure difference to an operating beam. The beam is
restrained by an adjustable spring. When the force on the
beam overcomes the spring tension, the beam moves and
operates a switch or switches. On reduction of the applied
pressure difference the force applied to the beam also
falls, the beam is restored to its original position by the
spring, and the switch or switches resets.
INSTALLATION
The instruments are designed to be mounted vertically.
They can be mounted either direct to process or to a wall
or panel using the back plate provided. Select the
mounting point so as to avoid excessive shock, vibration or
temperature fluctuation. Instruments should be mounted
to avoid excessive heat transfer from the process line or
adjacent plant.
If sudden changes of pressure (pulsations) are likely then
we recommend that snubbers are fitted between the
process line and switch.
COMPOUND RANGES eg –2.5 to +2.5 mbar
For normal operation negative pressure is applied to
the LP port whereby the HP port is left open to
atmosphere and the set point is between 0 and +2.5
mbar. For reverse operation, negative pressure may
be applied to the HP port whereby the LP port is left
open to atmosphere and the set point is between 0
and –2.5 mbar. For positive pressures the opposite
applies. It is recommended the minimum setting to be
not less than 5% of Full Scale (FS) either side
approaching zero (see Fig 4).
NOTE: For accurate setting, a suitable pressure
gauge must be used in conjunction with the above
procedure. Do not attempt to set the switch outside
the scale limits. Thought the unit may be set
anywhere within its operation range, for optimum
performance, it is good practice to have a set point
value between 25% and 75% of span.
REPLACEMENT PARTS
Use only factory authorised parts and procedures.
The only parts normally recommended for site
replacement are the microswitches. However, in some
circumstances other spares kits are available. Apply
for details quoting the serial number and full product
code.
WARRANTIES – SEE CONDITIONS OF SALE.
SPDT
NC = NORMALLY CLOSED
COM = COMMON
NO = NORMALLY OPEN
2 x SPDT
REAR (LO) FRONT (HI)
SWITCH SWITCH
FIG 1
LOCKING PLATE
SCALE PLATE
INSTALLATION, OPERATING AND
MAINTENANCE INSTRUCTIONS FOR
DIAPHRAGM ACTUATED SERIES 300
PRESSURE DIFFERENCE SWITCHES
(MODELS 306 & 386)
ISSUE G 02/10
PRODUCT CODE
ENCLOSURE
MODEL
ELECTRICAL ENTRY
MATERIAL OF WETTED PARTS
RANGE
SWITCHING OPTIONS
PROCESS CONNECTION
OPTIONS AND TREATMENTS
SPECIAL ENGINEERING
Use a spanner to support the process connection when
fitting the instrument. DO NOT OVER-TIGHTEN. When
fitting the instrument lid make sure gaskets or ‘O’ rings are
in good condition and fitted correctly.
On enclosures H and K, remove the lid using an
appropriate tool if tight use edge of a spanner or metal rod
(fig 5).
WARNING: CHECK THE CONNECTION THREAD SIZE
AND SPECIFICATION ON THE UNIT TO AVOID
MISMATCHING WITH THE PROCESS CONNECTION
ADAPTOR. SEE DIGIT 11 OF PRODUCT CODE.
ALL DIMENSIONS mm (inches)
5 % FS MIN
DEAD BAND
To remove lid on enclosures H, K, M loosen and
rotate lid locking device (refer to fig 8). Where lid is
tight use a flat bar, refer to recommended sizes
below. Material needs to be hard chrome steel
spanner grade.
The edge of a spanner may be used.
11 (.43)
Fig 5
(1)
(0.21)
LOCKING SCREW
LOCKING SCREW
SCALE PLATE
SCALE PLATE
(LOW)
ADJUSTING
INDICATOR
LOCKING SCREW
FRONT TOP VIEW
OF SWITCHING
MECHANISM
PRESSURE
DIFFERENCE
0
PRESSURE
DIFFERENCE
Fig 4
350 (13.7) MIN.
All Dimensions mm (inches)
In the interest of development and improvement Delta Controls Ltd, reserve the right to amend without notice,
details contained in this publication. No legal liability will be accepted by Delta Controls Ltd, for any errors,
DELTA CONTROLS LIMITED, ISLAND FARM AVENUE, WEST MOLESEY, SURREY KT8 2UZ
T +44 (0) 208 939 3511 F +44 (0) 208 783 1163 E sales@delta-controls.com W www.delta-controls.com
WIRING (Fig 1)
Wire in accordance with local and National codes. Use
cables no larger than 2.5 mm2 (14AWG). Deliver electrical
connection through a suitable cable gland, which will
maintain the IP rating of the instrument. Insert bare wires
fully into the terminal block and tighten securely. Keep
wiring tails to a minimum and check that wires do not
interfere with the operating mechanism. Use the earthing
points provided.
CERTIFIED ENCLOSURES
All Series 300 Pressure Difference Switches can be
supplied with BASEEFA certified enclosures to the
following standards:
Zone 1 (Div 1) IEC 60079-0 and IEC 60079-1
BS 5501:Parts 1 and 5: EN50 014 and EN50 018
CENELEC Codes ‘H’ for aluminium and ‘K’ for cast iron
2GD Exd IIC T6
Zone 2 (UK only)
BS 4683: Part 3, Enclosure Code ‘N’. ExN IIT6.
All enclosures are suitable for outdoor use and the majority
of products are rated IP66. Refer to the product label
and/or leaflet. Only operation, maintenance or repair
procedures either contained herein or approved by Delta
Controls may be used, to avoid rendering the equipment
unsafe in operation and/or nullifying the Certification. NO
MODIFICATIONS ARE PERMITTED.
Electrical Adaptors
Zone 1. Use only certified adaptors for Zone 1.
WARNING: IT IS A REQUIREMENT OF SAFETY THAT
AT LEAST 5 FULL THREADS ARE ENGAGED
BETWEEN THE ADAPTOR AND CONDUIT ENTRY.
TAKE CARE TO SELECT AND INSTALL ADAPTORS
THAT DO NOT REDUCE THE ENCLOSURE IP RATING.
Zone 2.
Adaptors used must have equivalent IP rating to the
enclosure and be impact resistance to 7 Nm.
References for Selection and Installation
BS 5345 Part 3 for Enclosure Codes H and K
BS5345 Part 4 for all Enclosure Codes (Intrinsic Safety)
BS 5345 Part 7 for Enclosure Code N
BS 5490 IEC 529 EN 60529 IP RATING (Ingress
Protection)
MAINTENANCE
Inspections should be carried out at quarterly to yearly
intervals depending upon operating conditions.
Isolate the unit from process and power and remove the
lid. Check all terminals for tightness. Check that cable tails
are not fouled or chafed. Check for internal condensation.
Rectify as necessary.
It is recommended that instruments used to provide an
alarm are operated periodically to ensure they are
functioning correctly.
If further maintenance is required seek advice from DELTA
CONTROLS before attempting repair or replacement of
parts.
CAUTION
Moving parts have been treated with a water repelling
lubricant before leaving the factory. Occasional inspection
and the application of a water repelling lubricant is
recommended to ensure moving parts remain free under
all conditions.
* 167 (6.57)
CONNECTION
MODELS W, N 306, 386 RANGES B2 TO C6
(5.47)
(0.27)
CONNECTION
FIG 8
MODELS W, N 306, 386 RANGES E1 TO J0
YOUR TRUSTED PARTNER IN PROCESS INSTRUMENTATION
Registered Office Registered in England No 5369683
12 (0.48)
122 (4.8)
7
7
75
FIXING SCREW
RETAINING
SCREWS
ENTRY
(7.95)
SCREW
CONNECTION
*INCREASE BY 10 (0.39) ON ENCLOSURE N
DIM 'D'
DIM 'C'
DIM 'B'
(4.6)
(8.77)
11 (0.43)
FIG 6
174 (6.85)
154 (6.06)
10 (0.39)
FIXING
CENTRES
7
CONNECTION
7 (0.27)
154 (6.06)
B2 W & N 255 (10.0) 121 (4.75) 149 (5.86) 259 (10.19)
H & K 255 (10.0) 109 (4.29) 149 (5.86) 259 (10.19)
B3/B5 C6 W & N 160 (6.29) 77 (3.03) 104 (4.09) 164 (6.45)
H & K 160 (6.29) 65 (2.55) 104 (4.09) 164 (6.45)
omissions or amendments.
CONNECTION
* INCREASE BY 10 (0.39) ON ENCLOSURE N
95 (3.74)
41 (1.61)
77 (3.03)
156 (6.14)
ENTRY
51 (2)
WARNING: DOES NOT APPLY TO OXYGEN SERVICE.
Zone 1 enclosures
Thread seal and contact surfaces must be lightly lubricated
using a non-setting non-corrosive grease compatible with
the nitrile lid seal. Do not use copper bearing grease on
aluminium. Screw on lid hand tight making sure that
mating surfaces of the lid and enclosure are in contact.
Re-tighten the lid lock screw.
WARNING: IT IS A SAFETY REQUIREMENT THAT AT
LEAST 5 FULL THREADS ARE ENGAGED WHEN THE
UNIT IS IN OPERATION. NEVER OPERATE THE UNIT
UNLESS THIS CONDITION IS MET. DO NOT USE
GREASES OR LUBRICANTS NOT COMPATIBLE WITH
THE ENVIRONMENT OR PROCESS.
Weather-proof Enclosure (W) and (N).
If lid gasket is dried out or damaged, replace with new
greased gasket.
OPERATION
Pressure difference switches are supplied calibrated
against falling pressure difference unless otherwise
specified. Set Point adjustment refers to falling pressure.
Switching differential is the difference between the set
point and the operating value on rising pressure. Before
commencing adjustments or removing the lid, isolate the
instrument from process and power. For opening details
see Fig 5 to 8.
Set Point Adjustment: Model 306 (Fig 2)
1. Loosen the M3 hexagon head locking screw.
2. Rotate the 20 mm A/F hexagon head adjuster knob to
move the indicator along the calibrated scale. Rotate
clockwise to increase the set point and counter
clockwise to decrease the set point.
3. Retighten the locking screw taking care not to over
tighten.
4. Replace the instrument lid (see maintenance).
Set Point Adjustment: Model 386 (Fig 3)
The model 386 provides 2 microswitches, which can be set
independently against individual scales using a special
dual beam mechanism. This fulfils the need for HI LO
switching. Adjust as follows:
1. Loosen the rear M3 hexagon head locking screw.
2. Rotate the rear adjuster screw to move the indicator
3. Retighten the locking screw.
4. Loosen the front hexagon head locking screw.
5. Rotate the front adjuster screw to move the indicator
6. Tighten the locking screw.
7. Replace the instrument lid (see maintenance).
PROCESS CONFIGURATIONS
For normal pressure difference operation, the connections
are made to the High Pressure (HP) and Low Pressure
(LP) ports as appropriate. For single ended positive
pressure operation the HP only is used and the LP is left
open to atmosphere. Use a breather/filter in the vacant
port of single-ended operation.
(8.35)
CONNECTION
(0.39)
FIXING
CRS
(0.27)
MODELS H, K 306, 386 RANGES E1 TO J0
on the right hand (LO) calibrated scale. Rotate
clockwise to increase the set point and counter
clockwise to decrease the set point.
on the left hand (HI) calibrated scale. Rotate
clockwise to increase the set point and counter
clockwise to decrease the set point.
7
(0.27)
168 (6.61) DIA.
DIA 'A'
14 (0.55)
248 (9.76)
SOCKET CAP
(ROTATE)
CONNECTION
ENTRY
FACILITY
SCREW
DIM 'C'
DIM 'B'
121 (4.76)
(10.59)
FIXING
CRS.
FIG 7
MODELS H, K 306, 386 RANGES B2 TO C6
174 (6.85)
CENTRES
156 (6.14)
39 (1.53)
84 (3.3)
14 (0.55)
ENTRY
FACILITY
HP CONNECTION
CONNECTION
61 (2.4)
7
LP CONNECTION
154 (6.06)
FIG 9
Stock No: 002522/306
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1 A @ 1 2 5 V A C R E S I S T I V E ( IE C 1 0 5 8
Low Voltage Directive (LVD) – 2006/95/AC. Switch products with enclosure codes ‘W’ and
‘A’ supplied CE-marked must be installed and used in accordance with the main instructions
and this addendum supplied with each product. Products rated lower than 50V ac and 75 V dc
are outside the scope of the LVD, and therefore, do not require CE-marking under this
directive. The LVD does not apply to products with enclosure codes ‘H’, ‘K’, ‘R’, ‘N’ for use in
hazardous areas. Switch products with enclosure codes ‘H’, ‘K’, ‘R’, ‘N’, are covered by the
Explosive Atmospheres Directive ATEX – 94/9/EC and when CE-marked will indicate
compliance with this directive alone. The following directives do not apply to switch products
manufactured by Delta Controls:
Electromagnetic Compatibility EMC – 2004/08/EC.
Machinery Safety Directive MSD – 2006/42/EC.
ENCLOSURE ‘W’
Cable Glands and adaptors – If enclosure ‘W’ is supplied with a through hole of 22 mm
blanked with a blind grommet. Discard the grommet and fit a suitable proprietary brass or
nylon M20 cable gland with thread length of 10 mm and locknut. Fit the nylon reducer provided
to the inside and a fibre washer to the outside. See diagram 1.
Alternately, the enclosure may be supplied from the factory with a threaded adaptor ready to
accept the customer’s gland or conduit system.
Alternatives:
i) a metal or nylon adaptor may be used to accommodate other sizes of gland eg NPT, or
conduit system. See diagram 2.
ii) an elbow kit may be supplied to enable the entry to be rotated axially through 90° and
radially through 360°. See diagram 3.
Earthing / grounding – The user must make suitable local earthing arrangements, if required,
to ensure that metal glands are earthed.
An earthing point is provided inside the enclosure. If this is disturbed in any way it must be
reassembled correctly to be an effective earth and prevent ingress. See diagram 4. When
removing the lid slacken the M4 nut first and ensure it is re tightened whenever the lid is
replaced. See diagram 4.1.
ENCLOSURE ‘A’
Cable Glands and adaptors – Enclosure ‘A’ is supplied with an M20 x 1.5 tapped hole. Use a
suitable stainless steel cable gland and sealing washer. Alternately the enclosure may be
supplied with a threaded adaptor fitted at the factory ready to accept the customer’s gland or
conduit system. See diagram 5.
Earthing / grounding – Bonding between the enclosure and gland / adaptor will be achieved
when both parts are screwed together. An earthing point is provided inside the enclosure. If
this is disturbed in any way it must be reassembled correctly to be an effective earth and
prevent ingress. See diagram 4.
EARTHING / GROUNDING OF PROCESS CONNECTION AND BACK PLATES – All the
internal dead metal work is bonded to the enclosure earthing point. Due to requirements of
sealing, the process connection and back plates may be isolated from the earthing point. Do
not, therefore, rely on either for earthing, instead always use the earthing point provided. If
required, the process connection and back plates may be bonded locally. Never use the
process connection or inlet pipe for locally grounding welding equipment unless it is separately
earth bonded.
Declaration of Conformity
We: Delta Controls Ltd
Island Farm Avenue
West Molesey
Surrey, UK
KT8 2UZ
As the manufacturers of the apparatus listed, declare under our sole responsibility that the products listed
below:
Pressure, Pressure Difference, Temperature & Flow switches series “W” or “A”:
201, 202, 203, 281, 204, 207, 208, 209, 231, 232, 233, 234, S21, S22, S24, GR2, GR4, VM2, VM4.
301, 303, 304, 381, 384, 306, 386, 310, 316, S31, S34, GR3, GR6.
721, 731, 771, 722, 732, 772, 723, 733, 773, 781, 734, 774, 741, 742, 743, 744, S71, GR7.
131.
To which this declaration relates are in conformity with the following relevant standards or parts thereof:
EN 60947-1 :1992 Low voltage switch gear and control-gear-general rules.
EN 60947-5-1:1992 Low voltage switch gear and control-gear-control circuit devices and switching
elements.
EN 60529: 1991 Specification for classification of degrees of protection provided by enclosures.
EN 60950:1992 Safety of information technology equipment including electrical business equipment:
section 2.5.
BS 6134:1991 Specification for pressure and vacuum switches.
And thereby conforms to the requirements of the Low Voltage Directive 73/23/EC amended by 93/68/EEC.
………………….
R. Harrison
Managing Director
Original dated 22nd June 2000
Rev. B dated 12
th
August 2009
Signed:
conditions where condensation may readily form, then sealed contacts should be used. See
Table A codes 08/09, 0G/0H, H2/H3/H6.
Electrical isolation – These products are not suitable for electrical isolation. Always isolate
circuit separately to carry out any electrical work.
S W I T C H C O D E
5 A @ 1 1 0 / 2 5 0
0 0
&
0 1
5 A @ 1 1 0 / 2 5 0
0 2
&
0 3
&
0 5
0 8
&
0 9
&
0 H
5 A @ 1 1 0 / 2 5 0
5 A @ 1 1 0 / 2 5 0
0 D
5 A @ 1 1 0 / 2 5 0
H 2
&
H 3
&
H 6
M I C R O S W I T C H
( R E S I S T IV E )
* S E E N O T E
2 A @ 3 0 V D C
1 A @ 1 2 5 V A C
* 1 0 0 m A @ 3 0
1 1 0 / 2 5 0 V A C
5 A @ 3 0 V D C
* 1 A @ 3 0 V A C
2 A @ 3 0 V D C
2 A @ 3 0 V D C
– all products are suitable for use in pollution degree 3. For extreme
R A T I N G
V A C
V A C
( I e I U e )
Uimp
Ui
1 2 0 / 2 4 0 V A C
V
1 2 5 / 2 5 0 V D C
1 2 0 / 2 4 0 V A C
&
U t i l i s a t i o n
C a t e g o r y
D 3 0 0
R 3 0 0
D 3 0 0
V
V D C
* 5 A @
& 3 0 V D C
V A C
V A C
1 2 5 / 2 5 0 V D C
1 2 0 / 2 4 0 V A C
1 2 5 / 2 5 0 V D C
1 2 0 / 2 4 0
V A C
1 2 0 / 2 4 0 V A C
R 3 0 0
D 3 0 0
R 3 0 0
E 1 5 0
D 3 0 0
D 3 0 0
V
V A C
1 2 5 / 2 5 0 V D C
1 2 0 / 2 4 0 V A C
R 3 0 0
D 3 0 0
V
1 2 5 / 2 5 0 V D C
R 3 0 0
C
C
C
Make
Bre a k
T h e e l e ctr i c a l r ati n g i s d e p ende n t o n t he m i c r oswit c h f i tte d t o t h e
in s t r u m en t . T he e l e c t rical r a t i ng i s d efin e d b y e a c h a p pro v a l t hat t h e
m i c r o s wit c h c o m p lies wi t h a n d i s s hown on t h e p r o d u ct na m e p l ate , i e U L /
CS A , or I E C . I t s h o u l d b e n o ted t h a t t h e s w i t c h m u s t be u s e d w i t h i n t h e
el e c t r i ca l r ati n g sp e c i f i ed f r o m t h e a p p r o v al y o u r e q u i re. T a b l e A l is t s the
ac t u a l I E C r a t i ngs ag a i n s t t h e D e s ign a t i o n & U t i l i sati o n C a t e g or y m ark e d
on t h e n a m epl a t e . I n t h e a b s e n ce o f a n y v e r i fic a t i o n b y UL / C S A t h e
m i c r o s wit c h * m anu f a c t urer’ s r a t in g i s sp e c i f ied i n b o l d i t a l i c s. I f in
do u b t , see k g u ida n c e f rom f a c t o ry.
DIAG 1
ENCLOSURE WALL
DIAG 2
LOCKNUT
NYLON 22/20
DIAG 3
GLAND
FIBRE
SCREW
WASHER
DIAG 4.1
M4 NUT
M4 SINGL E
EARTH STRAP
FIBRE WASHER
ENCLOSURE
WALL
ELBOW ASSY
GASKE T
O RING
SEAL
PROPRIETARY
GLAND
½" NPT Pg 13.5
M20 X 1.5 ¾ ET
M4 PLA IN
WASHE R
EARTH
BASE
‘W’ ADAPTOR ASSY
EAR TH LABEL
SING LE
COIL
W AS HER
NUT
PLAIN
W AS HERS
NUT
STAR W A SH ER
DIAG 5
ENCLOSUREM20 x 1.5
CABLE GLAND /
CONDUIT ADAPTOR
DIAG 4
ENC LO SU RE W A LL
(E XT ER IOR)
BON DE D SE AL
SCR EW
EAR T HING ASSY
FIBRE WASHER
ADAPTOR
‘A’ ADAPTOR