Manual

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
MIS-APPLICATION 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. DO NOT
REMOVE OR REPLACE WITH ANY OTHER DEVICE
NOT APPROVED BY DELTA CONTROLS.
CAUTIONS
1. Maximum single-ended or out-of balance
pressure or vacuum;
Ranges B3, B5, C2, C5 = 60 mbar
Range D5 = 100 mbar
Ranges D2, D8, F1, G0, G8 = 7 bar
All model 310 ranges are only suitable for dry gaseous
mediums. Impulse lines should be sized and installed
to avoid condensation build up affecting accuracy.
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 resets.
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 recommended for site replacement is
the microswitch.
WARRANTIES – SEE CONDITIONS OF SALE.
PRODUCT CODE
ENCLOSURE
MODEL
ELECTRICAL ENTRY
MATERIAL OF WETTED PARTS
RANGE
SWITCHING OPTIONS
PROCESS CONNECTION
OPTIONS AND TREATMENTS
SPECIAL ENGINEERING
INSTALLATION
The instruments are designed to be mounted vertically
with the process connection underneath as shown in
Figs 4 & 5, using the mounting brackets 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.
WARNING: THE PROCESS CONNECTION
THREAD SIZE IS Rc1/4 AVOID MISMATCHING
WITH THE PROCESS CONNECTION ADAPTOR.
AVOID OVER-TIGHTENING ADAPTORS OR
DAMAGE MAY OCCUR.
WIRING (Fig 1)
Wire in accordance with local and National codes.
Use wire suitable for terminal screw and cup washer
provided on the microswitch. Deliver electrical
connection through a suitable cable gland which will
maintain the IP rating of the instrument. Keep wiring
tails to a minimum and check that wires do not
interfere with the operating mechanism. Use the
earthing points provided.
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.
WARNING: DOES NOT APPLY TO OXYGEN
SERVICE.
OPERATION
Pressure difference switches are supplied calibrated
against falling pressure difference unless otherwise
specified. Set Point adjustment refers to falling
pressure difference. Switching differential is the
difference between the set point and the operating
value on rising pressure difference.
For opening details see Fig 4 and 5.
Set Point Adjustment: Models 310, 316 (Fig 2)
1. Isolate from process and power.
2. Remove the instrument lid.
3. Loosen locking plate by slackening the M3
hexagon screw.
4. Rotate the adjuster screw with a plain blade
screwdriver to adjust the set point. Rotate
clockwise to increase the set point and counter-
clockwise to decrease the set point. The scale
provides an approximate set value (see note).
5. Re-tighten the locking screw.
6. 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.
For single ended negative pressure operation the LP
only is used and the HP is left open to atmosphere.
Use a breather/filler in the vacant port of single-ended
operation.
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 3).
ISSUE G 07/09
INSTALLATION, OPERATING AND
MAINTENANCE INSTRUCTIONS FOR
DIAPHRAGM ACTUATED PRESSURE
DIFFERENCE SWITCHES
SERIES 310/316
C OMM ON
N ORM AL LY
OPEN
N ORM AL LY
C LO SE D
4
1
2
Fig 1
Fig 2
ADJUSTER
SCREW
ADJUSTER
LOCK
MICROSWITCH
RANGE
SPRING
LP
HP
5% FS MIN
DEAD
BAND
0
NORMAL
PRESSURE
DIFFERENCE
REVERSE
PRESSURE
DIFFERENCE
Fig 3
FIXING CENTRES
7 (0.67)
51 (2)
102 (4)
51 (2)
13 (0.5)
34
(1.33)
102 (4)
FIXING
CENTRES
16 (0.62)
16
(0.62)
20
(0.8)
70 (2.75)
112 (4.4)
4 MOUNTING FEET WITH
HOLES SUITABLE FOR
6 mm (0.24) DIA FIXING
SCREWS
ELECTRICAL ENTRY
CENTRE LINE
PROCESS
CONNECTIONS
Fig 4
LP
HP LP HP
ALL DIMENSIONS mm (inches)
ALL DIMENSIONS mm (inches)
(0.57)
(1.18)
(2.75)
ELECTRICAL ENTRY
CENTRE LINE
4 MOUNTING FEET WITH
HOLES SUITABLE FOR
6 mm (0.24) DIA FIXING
SCREWS
(1.25)
PROCESS
CONNECTIONS
(0.62)
FIXING
CENTRES
FIXING CENTRES
13
(0.5)
16
32
102 (4)
51 (2)
51 (2)
102 (4) 127 (5)
142 (5.6)
98 (3.85)
70
14.5
30
HP
LP
HP
LP
Fig 5
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,
omissions or amendments.
YOUR TRUSTED PARTNER IN PROCESS INSTRUMENTATION
DELTA CONTROLS LIMITED, ISLAND FARM AVENUE, WEST MOLESEY, SURREY KT8 2UZ
T [phone] F [phone] E [e-mail] W www.delta-controls.com
Stock No: 002522/310
Registered Office Registered in England No 5369683