delta-mobrey Performance Series Guide

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IOM-PERFORMANCE-B : SEPT 2019
Installation, Operation &
Maintenance Instructions
Performance Series
Model 131 (Flow Switch)
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.
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.
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.
Operating principles
Flow Switch 131 is vane actuated switch.
The sensing element is a pivoted, counter-weighted
vane, which at its rest position lies at right angles to
the direction of flow. The vane is mounted on a shaft,
which carries two cams that operate one or two
microswitches when the shaft is rotated. When the
nominated flow velocity is reached the vane turns
the shaft enough to operate the switch(es).
Two springs constrain the shaft movement. One
compensates for any gravitational effects on the
vane and for the internal spring setting of the switch
(es). The other determines the amount of flow on the
vane to operate the switch(es). 
INSTALLATION
Mounting (All models)
The instruments may be used on flow in any
direction with the operating shaft horizontal or
vertical. The instrument is supplied with the
microswitch set to operate correctly in relation to
rotation of the operating shaft. Vane and counter
weight are supplied separately. Select the mounting
point so as to avoid excessive shock, vibration or
temperature fluctuations. Install far enough away
from bends, tees or obstructions to avoid non-steady
flow. Instruments should be mounted to avoid
excessive heat transfer from adjacent plant.
Provide aperture in duct large enough to accept
counterweight / vane (refer to fig 1). Position the
vane assembly axially along the operating shaft
which may be adjusted to a maximum of 100 mm
from the mounting plate to the vane centre line by
tightening the M3 socket set-screw provided,
ensuring that the screws locate on flat of shaft.
Fig 1

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IOM-PERFORMANCE-B : SEPT 2019
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 / grounding points
provided.
End of line resistors
Some products may be supplied to order fitted with
end of line resistors. Resistors in use may generate
a heat source. The type, quantity, configuration,
fitment method and allowable electrical loads are
limited by the scope of the certification.
NEVER FIT END OF LINE RESISTORS OR
MODIFY WITHOUT REFERENCE TO
DELTA MOBREY
Replacing cover / lid on
Flameproof enclosures
BEFORE CLOSING THE LID:
 ENSURE WIRE IS CLEAR OF ALL
MOVING PARTS.
 ENSURE THAT WIRES DO NOT
TOUCH THE LID AS IT IS CLOSED.
Thread, seal and contact surfaces may be lightly
lubricated using a non-setting non-corrosive grease
compatible with the lid seal.
DO NOT USE COPPER BEARING
GREASE ON ALUMINIUM.
Before connecting to electrical power,
screw on cover/lid hand tight making
sure that mating surfaces of the lid and enclosure
are in contact. Use the locking screw provided to
prevent casual and unauthorised removal of the
cover/lid.
IT IS A SAFETY REQUIREMENT THAT AT
LEAST 5 FULL THREADS ARE ENGAGED
BETWEEN THE COVER / LID AND THE
ENCLOSURE WHEN THE UNIT IS IN
OPERATION. NEVER OPERATE THE
UNIT UNLESS THIS CONDITION IS MET.
ATEX
ATEX
ATEX
ATEX
Installation of electrical adaptors and
cable glands to the electrical entry
Either one or two electrical entries can be provid-
ed. The standard entry is a single ISO M20 x 1.5
thread. Other non-ISO and tapered threads will
have their size and type stamped on the enclosure
next to the entry.
TAKE CARE TO SELECT AND INSTALL
ADAPTORS THAT DO NOT REDUCE
THE ENCLOSURE’S DEGREE OF PRO-
TECTION WHEN IN USE IN ZONE 1
HAZARDOUS AREAS.

UNUSED ENTRIES MUST BE FITTED
WITH SUITABLY CERTIFIED FLAME-
PROOF STOPPING PLUGS.


IT IS A SAFETY REQUIREMENT THAT
AT LEAST 5 FULL THREADS ARE EN-
GAGED BETWEEN THE ADAPTER,
CABLE GLAND OR STOPPING PLUG,
AND THE ELECTRICAL ENTRY WHEN
THE UNIT IS IN OPERATION. NEVER
OPERATE THE UNIT UNLESS THIS
CONDITION IS MET.
Alternative electrical entry threads
One or two electrical entries can be supplied with
the following optional thread types:
 ISO to BS 3643 (1981) medium fit 6H up to
M25 x 1.5
 DIN 40430 (1971) up to Pg21.
 USAS B2.1 (1968) gauging to clauses 36 & 37
up to 3/4" NPT.
 BS conduit to BS31 (1940) table 'A' up to 1"
 BSP to BS21(1985) standard threads only as
clause 5.4 gauging to clause 5.2 system 'A' up
to Rp3/4 (medium fit or better).
Wiring
DISCONNECT ALL SUPPLY CIRCUITS
BEFORE WIRING
WIRE IN ACCORDANCE WITH LOCAL
AND NATIONAL CODES. USE CABLES
NO LARGER THAN 2.5 MM 2 (14 AWG)
DO NOT EXCEED ELECTRICAL RAT-
INGS STATED IN LITERATURE AND ON
NAMEPLATES.
The three switch terminals are clearly marked
“NORMALLY CLOSED”, “NORMALLY OPEN” and
“COMMON”. The following diagram can be used as
a guide for wiring.


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ATEX
ATEX
Fig 2

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IOM-PERFORMANCE-B : SEPT 2019
Changing direction of flow
(Model 131) (See fig. 4, 5):
If when installed the direction of operation is wrong
this can be reversed in situ as follows (refer to figs 4
& 5):
1. Remove springs S1, S2
2. Remove two M3 screws and reassemble plate P
as shown in fig 4.
3. Replace two M3 screws.
4. Replace spring S1 on pin 2.
5. Replace spring S2 on pin 1.

2xSPDT
Both cams are accessible with the enclosure cover
removed and may be adjusted by slackening two M3
hexagon headed screws. Normally the cams are set
to operate each microswitch simultaneously at
approximately 15° from the vertical. This may be
altered in situ if desired to offset the operation of
each microswitch individually or position the
operation of both microswitches for a different vane
angle. However, it is recommended that at least 5°
clearance between operation of microswitches and
stops is allowed for safety. After changing flow
direction, it may be necessary to alter the cam
position, to prevent the cam adjustment screw heads
from hitting the microswitch bodies before the stop
pins hit the stop plate.
OPERATION
THIS UNIT CONTAINS POTENTIALLY
SPARKING CONTACTS. DO NOT
REMOVE THE COVER / LID WHILE
ELECTRICAL POWER IS CONNECTED
TO THE SWITCH AND / OR WHEN A
FLAMMABLE GAS ATMOSPHERE IS
PRESENT.
Each vane assembly is supplied factory counter
weighted and requires no site adjustment. However,
the vane assembly is supplied loose and will require
fitting to the instrument before setting. The
instrument is supplied with the microswitch(es) set
to operate correctly in relation to rotation of the
operating shaft and red springs fitted to give
maximum sensitivity to low flow.
Set point adjustments (Model 131)
(See fig. 4):
Fig 3 gives an indication of flow rates covered by the
2 vane sizes. Reference to this will help select which
vane to fit before setting.
ATEX
1. Isolate the instrument from supply.
2. Remove the instrument lid.
3. Adjust springs as required by rotating the M4
hexagon screws: turn clockwise to increase the
setting and counter-clockwise to reduce setting.
A 7mm A/F spanner will fit these screws
4. Alternative springs are supplied to cover the full
range of operation from 2.5 to 12.5 metres/
second (fig 3). These may be used singly or in
pairs as the user desires, provided the lowest
setting is sufficient to return the vane safely on
no flow. Each spring may be adjusted via an M4
hexagon screw, rotating clockwise to increase
tension and thus reducing flow sensitivity.
Fig 3
Fig 4
Fig 5

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IOM-PERFORMANCE-B : SEPT 2019
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
MOBREY before attempting repair or replacement of
parts.
SPECIAL CONDITIONS FOR SAFE USE
This note relates to flameproof models with ATEX
certification number BAS01ATEX2426X.
The apparatus has a specified flamepath with a
diametrical clearance of 0.1 mm maximum
associated with the push rod and bush assembly
passing through the enclosure wall, which is less
than the maximum permitted by the standard EN
50018-1:2000 to which the certification is issued.
The user shall ensure that, in service, the
diametrical clearance of this flamepath does not
exceed 0.1 mm.
NOTE: Under normal operating conditions where
the process is not continually cycling above and
below the set point, the wear will be minimal. To
examine for wear remove the pressure sensor from
the bottom of the enclosure and examine the rod
and bush assembly for obvious wear. Do not attempt
to remove the assembly and if in doubt seek
assistance from Delta Mobrey.
Model 131
(Flow Pressure Switches)
DIMENSIONS