Download - Shutter Flow Meter Terminal Boxes - TERMAN

Shutter
Flow meter
Terminal boxes
Shutter
Flow Meter
Terminal Boxes
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Shutter Valve
DAROC
Description and general specifications
Production range and operating conditions
Operation
Installation, setting and putting in service
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Description and general specifications.
Transformer conservators are usually arranged in such a way that, even at minimum level, the oil is always
above the highest point of the transformer lid. When a leak occurs in the tank, due for example to a broken
bushing, the oil in the conservator pours out, thus considerably increasing the danger of fire and pollution.
The automatic conservator oil shutters DAROC Series DS and EDS-R have been designed to prevent the oil
contained in the conservator from flowing out when a leak occurs and, for Series EDS-R, to signal this by an
electric contact.
Main features of the DAROC shutters Series DS and EDS-R are:
ï They are mounted on the pipe from tank to conservator, in series with the Buchholz relay, so they can be
used both on conservators with free oil surface and on conservators with rubber bag;
ï The operation is completely automatic. When, due to a leakage in the tank, the oil flow rate from conservator
to tank exceeds a set value, the DAROC valve closes the pipe thus preventing the loss of the conservator
oil;
ï Should the DAROC valve trip unduly, because of a malfunction or of particular working conditions, a pre-set
by-pass valve operates automatically and prevents the internal depression in the tank from becoming excessive;
ï The DAROC shutter has to be reset manually after tripping; if requested an additional by-pass pipe allows
to reset the valve from ground level.
The shutting-off of the pipe between tank and conservator is always an abnormal operating condition; it is
therefore preferable to choose the DAROC Series EDS-R shutter in order to have a warning by electric contact
that the valve has tripped.
Production Range and Operating Conditions.
DAROC Series DS and EDS-R shutters can be fitted to pipelines of nominal diameter 50, 80 or 100 mm; The
valves can be equipped with one or two electric contacts and can operate under following conditions:
ï Oil and ambient temperature range : -25 C to + 120 C (standard version)
ï Oil features ( standard version ) : ◊ Mineral oil
◊ Oil viscosity 30 cStk at 20 C
Please note: with other oil viscosity the flow rates change according to the setting diagram
ï Vibration resistance : 3 g on all axis
ï Check resistance : 10 g on all axis
ï Maximum operating pressure : 1,5 bars
ï Maximum test pressure : 3 bars
ï By-pass valve setting ñ standard version 0,4 bars
ï Degree of protection : IP 65
Casing : made of cast aluminium and has two flanges for mounting onto the pipeline which connects the
tank to the conservator. One flange has threaded holes and a gasket groove so that the device can be fitted
directly to the Buchholz relay. On casing two windows allow to visually check the operation of the device and
two oil drain screws allow to empty the casing of oil if needed. The adjusting device and, if requested, the resetting
by-pass pipe are also assembled on casing.
The casing is closed by a cover which includes the terminal box for DAROC contacts equipped valves series
EDS-R, a gas drain cock and the nameplate, which shows also the direction in which to mount the DAROC
valve on the pipe, are attached to the head.
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Operation.
During the operation of an electric transformer several conditions may occur which cause an oil flow in the
pipe between tank and conservator:
ï During the heating phase an oil flow from tank to conservator is observed, due to oil expansion as the
transformer heats up; the flow rate is usually 30
dm 3 /min.
The first two conditions occur in normal service and should not cause the shutter Series DS and EDS-R
valve to trip.
The shutter is designed to trip automatically when the third condition occurs, thus stopping the oil
flow from conservator to tank and preventing the oil in the conservator from being lost and slowing
down the rate at which the oil seeps out at the leak.
The shutter doesnít operate when the oil flows from tank to conservator; it trips when the oil flow from conservator
to tank exceeds a set value.
To operate correctly, the valve has to be set so that the admitted oil flow from conservator to tank is the
maximum that will occur during the cooling phase. So, when a leak in the tank causes the oil flow to exceed
the maximum set the valve will close and prevent the oil in the conservator from being lost.
Damping System
To take into account peaks of flow speed caused by accidental occurrences such as start up of pumps, elasticity
of the tank or of the radiators, the closing of the main valve is retarded by a hydraulic damping system,
which stops the valve from closing for flow speed peaks.
After tripping due to an oil leak from the tank, the main valve has to be reset manually, either by the adjusting
device or by the optional by-pass pipe.
If the valve trips during the cooling phase, not withstanding the damping system described above, the valve
will open again automatically during the heating phase, when the oil will start to flow from tank to conservator.
Overpressure Valve Operation
The main valve may close even in absence of a leak in the tank, for example when the oil in the pipe is very
cold and therefore has a viscosity much higher than expected, or if the initial regulation has not been correctly
done.
In this case, the shrinking of the oil due to the cooling will cause an increasing negative pressure in the
tank, while the cooling phase lasts. To limit the value of this negative pressure an overpressure valve has
been built into the DAROC shutter.
Installation, Setting and Putting in Service.
Installation
The DAROC shutter must be fitted onto the pipe between tank and conservator. The flange has a gasket
groove and threaded holes in order to be able to fit it directly to the Buchholz relay. The gasket is supplied
with the valve.
If DAROC Series EDS-R is chosen, the electrical connection to the terminals has to be made according to
the wiring diagram attached inside of the cover of terminal box.
Setting
The DAROC shutter is supplied set to the maximum stroke of main valve. In fact, when there is a leak in the
tank, the flow rate is usually considerable higher than the flow rate admitted by the valve at full stroke with oil
of normal viscosity.
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Taking into service
After installation and setting it is possible to put the device in service by filling it up with oil.
Maintenance
The DAROC shutter doesnít need any particular maintenance; it is however advisable to check the correct
operation regularly.
Resetting of main Valve
If the main valve closes accidentally during the cooling phase of the transformer, it may be necessary to reset
it without having to wait for the heating phase. This can be done either by the forced opening screw or by
the re-setting by-pass.
Finish
In standard version, all cast parts are protected by one coat of two-pack epoxy primer and one coat of twopack
polyurethane paint, final colour RAL 7031 and screws and washer are of stainless steel; the degree of
mechanical protection is IP 65. Therefore the device is suitable for outdoor usage even in tropical climate
and with high industrial pollution. Special versions are available for particularly severe climatic and/or aggressive
atmospheric conditions.
Performances of contacts
Magnetically operated, normally open, normally closed or changeover contacts.
ï Contacts material : gold
ï Operating temperature : - 50 C - + 125 C
ï Breaking power : 150 W ñ 400 VA
ï Insulation : 2000V 50Hz between terminals and earth for a 60 seconds time.
ï Maximum current : 2 A
ï Minimum and maximum tension : 24 ñ240 V
ï Contact resistance : 500 mŸ
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Shutter ñ DAROC Type: EDS-R
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Oil Flow Meter
for Power Transformers type:
Description and general specifications
Operating instructions
SCFR - 2
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Description and general specifications.
Characteristics
The circulation indicators Series SCFR2 ( Oil Flow Indicators) are designed to check the circulation of dielectric
fluids, normally mineral oils, into the cooling plants of electric power transformers. It is possible to use
said indicators with other kind of fluids too. Only it is necessary to use the right materials which are compatible
with the circulating fluid.
The circulation is optically indicated by an indicating pointer that shows on a dial if the oil is circulating or not.
The optical indication may be not proportional to the flow velocity.
The indicator can be equipped with one or two contacts that operate alarms in case the flow speed inside of
the pipeline is lower than a minimum acceptable value.
The operation of the indicator Series SCFR2 is based on the dynamic thrust of the flowing oil on a detection
paddle placed inside of the pipe; the dimensions of the paddle depend from the diameter of the pipe. An adjustment
device allows the triggering point to be modified within certain limits, also after the indicator mounting
on the pipeline, in order to adapt it to the real flow conditions.
Field of use
The circulation indicators Series SCFR2 may be used with the following characteristic values:
ï pipeline diameter : from 80 to 400 mm
ï flow speed : from 0,5 to 3,0 m/sec
ï fluid : mineral oil
ï pressure inside of the pipeline : from 0,0 to 5,0 bar
ï working temperature from : - 20 C to + 120 C
ï resistance to vibrations : up to 3g on all axes
ï resistance to shock : up to 10g on all axes
Special features
Basing to the experience of the previous series, special features have been included in the design of the circulation
indicators Series SCFR2, with the aim of simplifying the choice of the device, granting easy interchangeability
and allowing the user to adapt the operating characteristics to the actual needs.
ï The big dial diameter and the bright colors of the figures and of the pointer consent easy reading from distance
too.
ï The construction si made in two separable parts: mounting flange, with detection paddle and adjustment
system, and indicator case with optical indication and alarm contacts. This construction allows the indicator
case removing for repairing or substitution or during the shipment of the transformer.
ï the transmission of the paddle movement is made by means of a magnetic transmission thus granting a
complete seal.
ï the adjustment system is simple and reliable; the adjustment can be made even after the device has been
mounted on the pipeline.
Operation instructions.
Construction features, finish and accessories
Case : aluminium alloy. Gray color painted
In standard execution, all cast parts are protected by one coat of two-pack epoxy primer and one coat of twopack
polyurethane paint, final colour RAL 7031. Screws and washer are in stainless steel
Closing ring : aluminium. Gray color painted
Lens : tempered glass
Paddle : brass
Degree of mechanical protection : case=IP 55 contacts =IP 67
Therefore the device is suitable for outdoor mounting even in tropical climate and with high industrial pollution.
Special versions are available for particularly severe climatic and/or aggressive atmospheric conditions.
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The device is supplied with its assembly gasket. A cable gland is supplied on request.
Wiring diagrams and contact performance
As mentioned above, the circulation indicators Series SCFR2 can be supplied with one or two electric
contacts.
Contacts Performances : 5A 250 VAC
0,25A 250 VDC
0,5A 125 VDC
Special contacts for electronic circuits having low current (1 to 100 mA) and voltage (4 to 10 V) can also be
supplied.
Operation
The circulation indicators Series SCFR2 operate as follows:
ï the oil flowing in the pipeline hits the detection paddle, thus causing the shaft on which it is mounted to
rotate by about 90 against the force of the return spring;
ï the dimension of the paddle is chosen according to the diameter of the pipe and the oil flow that it should
detect;
ï the tension in the return spring is pre-set at the manufacturing workshop in the middle of the adjustment
range set; the set point may however be further adjusted by turning the adjustment assembly after removing
the fixing screws; this adjustment can be made with the flange mounted on the pipe;
ï the magnetic joint transmits the rotation of the paddle to the indicating pointer and operates at the same
time the switches.
Mounting, adjustment and maintenance
Mounting
The device is mounted on a flanged stub pipe, welded directly to the pipeline; the dimensions of the stub
pipe should be as indicated in drawing N 12.600.10.
To mount the device on the pipeline, separate the indicator head from the flange by removing the lateral
screw and rotating the instrument by about 10 anticlockwise so as to free the screws from their holes; then
attach the flange to the pipe by screws M8, with the assembly gasket in groove.
After having attached the flange to the pipe, assemble the instrument's head on to the flange again
and check that the optical display is operating correctly by starting up and stopping the circulation pump.
If it is correctly working, make the cable layout according to the desired wiring diagram.
If the optical or electrical indications are not correct, carry out the adjustment described later.
In order to make sure the signal paddle is hit by the most uniform possible flow, avoid mounting the device
immediately downstream of bends, necks or other parts which could cause turbulence in the flow.
If this is impossible, the adjustment of the tension in the return spring, allows the indicator to be adapted to
the real flow conditions.
Adjustment
The device is always supplied with the adjustment assembly set to position 3, so that it is possible to both
increase and decrease the load of the return spring in order to set the device at a higher or lower flow rate.
If the factory setting is not satisfactory adjust the setting as follows:
ï remove the indicator head from flange as described above in order to get to the adjustment assembly
fixed on the flange by four screws.
ï remove the four screws; even if there is pressure in the pipe the adjustment assembly cannot come off the
flange; furthermore a gasket continues to guarantee the seal;
ï turn the adjustment block until the notch corresponds with one of the numbers on the flange, anticlockwise
to increase the force of the spring and trigger the device at a higher flow rate, and clockwise to have the opposite
effect;
ï replace the 4 screws and re-assembly the indicator's head on the flange; then check that the adjustment
made has the desired effect otherwise make a further adjustment.
Maintenance
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The circulation indicators Series SCFR2 do not need periodic maintenance; however it is advisable to
check regularly that they are operating correctly by starting up and stopping the circulation pump and
checking that the optical and electrical display takes place as normal.
Order specifications
When ordering it is necessary to indicate the type of device according to the table in drawing N
12.600.10, the diameter of the pipeline, the mounting position and the required wiring diagram. Standard cable
entry thread is æ.; should another thread be preferred and a cable gland be needed, this has to be mentioned
in order.
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Terminal Boxes Series
Description and general specifications
Operating conditions
Quality control tests
SM2
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Description and general specifications.
This specification concerns the function, the main features, the range of types, the assembly and operation
of the terminal boxes Series SM2. Environmental and operating conditions depend generally from the compatibility
of the materials and components and from the surface treatment.
Function
The measurement, control, check and data recording circuits for medium and high power, oilcooled,
oil-insulated electric transformers require medium and low voltage and current signals to be brought outside
of the tank.
The terminal boxes Series SM2 are designed and constructed to face this need since they offer oil-tight conductors
protected with a flanged casing and accessible through cable entries.
Construction features
The terminal boxes Series SM2 consist mainly of a flanged casing, closed by a cover, inside which are
mounted the terminals. One end of the terminal is wired inside of the transformer tank while the other end is
wired outside the tank through threaded cable entries.
The following data apply only to the terminal boxes Series SM2 fitted with M6 terminals.
General specifications
ï Flanged casing with lowered bottom to prevent air pockets; the casing has one or more cable entries and it
is closed by a cover; the mechanical protection degree is IP 65; identification labels inside and outside of the
box allow identification of terminal box as well as of terminals;
ï The cable entries are threaded to customer request and supplied on request either plugged by brass plugs
or with brass cable glands with gasket;
ï Terminal boxes are supplied with the number of terminals requested by customer;
ï The standard terminal is one-piece conductor threaded M6 at both ends for connection of a ÿ 6 mm cable
terminal; oil-tightness is obtained by O-Ring gasket;
ï The terminals are designed and mounted so that they cannot twist when the cable terminal is screwed on
and have a Snap-On ring to prevent accidental loosening during transport, handling and mounting; they are
evenly spaced so that they can be connected by connecting plates supplied on request;
ï The terminals are supplied with copper washers; inside of the tank self-locking nuts are used to assure secure,
vibration-proof wiring while the connection inside of the terminal box is assured with nut and counternut;
ï Terminals are numbered on both sides to ease cabling and allow identification;
ï Special M10 terminals are also available.
Materials and finish
ï Casing and cover of aluminium casting, painted with one coat of epoxy primer and one finishing coat of
polyurethane paint, colour RAL 7031; the epoxy primer is compatible with mineral transformer oil at a temperature
of up to 120 C, the paint passes the 500 hour salt fog test;
ï Nylon insulated nickel plated brass terminals with copper washers and vibration-proof nuts;
ï Terminal gaskets of fluor silicone rubber;
ï External screws and washers of stainless steel;
ï Cable entries are closed by plastic plug during shipment.
Operating conditions.
ï Environmental temperature with standard gaskets - 20 C to + 50 C
ï Relative humidity 95% at 20 C; 80% at 40 C; 50% at 50 C
ï Protection degree of box IP 65
ï Operating temperature (mineral oil) -20 C to +110 C
ï Insulation to earth of terminal at 20 C > 5.000 V
ï Standard M6 terminal cross section 12 mm2
Special versions can be supplied for other environmental conditions
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Quality control tests.
Following tests and controls are performed on boxes before despatch :
ï Insulation test of terminals towards box; test voltage 3.000V;
ï Tightness test of mounted terminals by compressed air and immersion in water bath; test
pressure 1 bar;
ï Control of correct numbering of terminals.
Range of types
The terminal boxes Series SM2 are produced in 4 types as follows :
ï Type SM2-X
◊ Dimensions to drawing N 15.112.00
◊ Number of terminals from 2 to 6
◊ Number and dimensions of cable entries 1 to 2 - max æî or PG 21or ÿ 35 mm
ï Type SM2-S
◊ Dimensions to drawing N 15.102.00
◊ Number of terminals from 2 to 12
◊ Number and dimensions of cable entries 1 to 3 - max 1î or PG 29 or ÿ 40 mm
ï Type SM2-L
◊ Dimensions to drawing N 15.136.00
◊ Number of terminals from 2 to 36
◊ Number and dimensions of cable entries 1 to 3 - max 1î or PG 29 or ÿ 40 mm
ï Type SM2-XL
◊ Dimensions to drawing N 15.236.00
◊ Number of terminals from 2 to 47
◊ Number and dimensions of cable entries 1 to 4 - max 11/2î or PG 42 or ÿ 50 mm
Drawings showing the construction of the terminals:
ï Terminal M6 N 15.102.001
ï Terminal M10 N 15.102.002
Assembly and operation
It is advisable to prepare a wiring diagram for each terminal box before assembling, showing the identification
of the terminal box, which can be engraved on the terminal box identification plate, and the correspondence
between the wire identification and the number of the terminal.
Terminal boxes Series SM2 are then mounted on the transformer tank as follows :
ï the wires inside of the tank are first connected to the terminals on the bottom of the terminal box in accordance
with the wiring diagram; for easy wiring and record it is advised to write the wire identification number
on the identification plate inside of the terminal box cover in correspondence to the number identifying the
terminal;
ï the terminal box is then bolted to the tank; the flange O-Ring gasket assures oil-tightness;
ï the external wires are then led inside of the terminal box through the cable entries, there to be connected to
the external part of the terminals; each wire has to be connected to the terminal following the numbering previously
set up;
ï if necessary one or more terminals can be connected by conducting plates that can be supplied separately;
ï when the wiring is finished close the cover of the terminal box.
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TERMINAL BOX SM2-X
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TERMINAL BOX SM2-S
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TERMINAL BOX SM2-L
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TERMINAL BOX SM2-XL
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Terman '90 S.r.l., Via Ghisalba, 13-20/21, 20021 Bollate (MI) ñ Italy. Tel: +39 02 38 30 37 12, Fax: +39 02 38 30 37 19, E-
Mail info@terman.com, www.terman.com
C.F./P. IVA IT 09970270154 ñ C.C.I.A.A. 1332904 ñ Trib. Milano Reg. Soc. 302729 ñ Cap. Soc. Ä 119.000
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