THERMOMETERS For distribution transformers - maxsteel

THERMOMETERS
For distribution transformers
Page 5.15 : Thermometer MTVT 84
Oil temperature indicator, new concept, fitted with two independent microswirches, range 0...120°C, only with bottom
entry rigid bulb.
Page 5.16 : Thermometers type BM (drg 1292)
Bimetallic oil temperature indicator, without contacts, range 0...120°C, with radial rigid stem or back entry, stainless steel
housing.
Page 5.17 & 5.19 : Thermometers type TESS
Oil temperature indicators, standard quality, for small distribution transformers, with two low speed contacts (low rating),
stainless steel housing, range 0...120°C
-(page 5.17 - drg 1290) with radial rigid stem, suitable for cover mounting
-(page 5.19 - drg 1365) Thermometer type TESS-B-100 with back entry stem and with two contacts (for side wall
mounting on transformers without conservator with nitrogen cushion)
-(page 5.19 - drg 1365) Vacuum-Pressure Gauge VPG-100 with two contacts (for side wall mounting on transformers
without conservator with nitrogen cushion)
Page 5.19.A & 5.20.A: Thermometers type TECED
High performance oil temperature indicators, organic liquid filled, for distribution transformers of bigger size or for small
power transformers, with low speed contacts (low rating), aluminium housing, range 0...120°C
TECED-R with radial rigid stem (pag 5.19..A)
TECED-Y with armoured flexible capillary (pag. 5.20..A)
HOUSING: Light aluminium alloy casting with glass window locked by a bronze ring
PROTECTION DEGREE: IP 55
OUTDOOR MOUNTING: Allowed
BREATHING DEVICE AND DRAIN SCREW: Supplied upon request, are necessary for the use of our thermometer in tropical climate
zones, in order to avoid moisturing inside the casing
STANDARD RANGE: 0...120 °C
PRECISION CLASS: +/- 1,5
MAX POINTER: Supplied upon request
CAPILLARY (only for form Y pag. 5.20A). Hermetically sealed capillary tube; bottom entry
Armouring: Copper tube or zinckplated flexible sheath inside a plastic tube
OIL IMMERSED BULB AND CONNECTOR: On pages 5.19.A and 5.20.A are shown the most commonly used styles, but it is possible
to supply tailor made executions, according to customer's specifications.
ELECTRIC CONTACTS: Two independent max contacts normally open (other wiring diagrams available upon request), air insulated,
slow speed action (these contacts must always work through a relay, never directly on the circuit breaker)
CONTACTS CHARACTERISTICS:
Insulation test at 2000 V/ 50 Hz
Rated voltage [V]
380
230
110
50
Rated current [mA]
dc ac / R load ac / ind. load
25
43
85
130
26
45
90
170
15
22
45
70
SPECIAL CONTACTS: Contacts may be fitted with two small magnets, with the scope of avoiding sparks between them, due to the
increased closing speed; consequently the current rating increases slightly, at a loss of precision of the temperature indication near to
the contact set point, and the contact opening The “Δt” has a small increase.
ORDERING INSTRUCTIONS: TECED type R or Y , nominal dial diameter, bulb style and connection, capillary entry - length -
armouring ( only for form-Y ), special requirements such as max pointer, breather, ground terminal, special wiring diagrams, special
range or other.
File : ACCESSORI DISTRIBUZIONE UNCONTROLLED COPY REV 04 dtd 09/10/09

OIL LEVEL GAUGES FOR DISTRIBUTION
TRANSFORMERS
MAGNETIC OIL LEVEL GAUGES
(without contacts)
Page 5.26. Type IML 80 and IML 99.
They are the two cheapest gauges of our range, with aluminium body, suggested to be used in distribution transformers
(max conservator diameter 400mm).
An arrow gives the indication of the oil level inside the conservator; they cannot be fitted with electric switches and they
can be supplied only in the "R" execution (float movement parallel to the dial).
SIDE WALL OIL LEVEL GAUGES
Page 5.34 (drg B 3190). Prismatic type.
They give an optic indication of the oil level inside a transformer tank or inside a conservator.
The steel frame must be bolted to the wall of an hermetic transformer or to the end of a conservator of a conventional
transformer.
File : ACCESSORI DISTRIBUZIONE UNCONTROLLED COPY REV 04 dtd 09/10/09

AIR DEHYDRATING BREATHERS
for distribution transformers
Type TV74-5-6 and VE05
1. GENERAL INFORMATION
Air dehydrating breathers are transparent hollow cylinder tubes which contain chemically pure silicium salt (silicagel) with
coloured indicator. The air breathed inside the transformer due to the thermal contraction of the oil mass, passes through
the silicagel.
The silicagel absorbs the humidity, indicating the saturation degree by changing colour as follows:
ORANGE silicagel completely dry.
WHITE silicagel saturated with humidity.
The salt contained in the breather, when saturated, may be easily removed and regenerated by heating it, inside a
ventilated oven, at 120° - 150°C, until the colour becomes orange again.
The specific property of the silicagel is its high absorption power of humidity. This is total until the salt has absorbed water
for about 15% of its weight, and saturation is reached when the salt has absorbed water for 30 to 40 % of its weight.
2. TECHNICAL FEATURES
The upper and lower parts are made in a non-porous corrosion-proof aluminium alloy casting. The hollow cylinder is
made of plexiglass and it is protected by a stainless steel cylinder, with windows which allow the visual control of the
silicagel colour.
In the bottom side of the breather, an hydraulic valve prevents continuous air contact with the silicagel and allows the air
to pass in both direction (inlet or outlet) only when there is pressure deficiency or excess inside the transformer.
Pressure values for air passage into the dehumidifier are:
0.003 kg/cm 2 inlet , or 0.005 kg/cm 2 outlet.
The hollow container and the hydraulic valve are separated by a drilled plate with a labyrinth system, which have the
double purpose of diffusing inlet air uniformly, and of avoiding that any salt dust may damage the closing system.
3. AIR DEHYDRATING BREATHER TYPE TV75 & VE05 (page 5.40)
They are small sized dehydrating breathers, particularly fit for assembling on small distribution transformers
The type VE05 follows the same manufacturing principles of the bigger sizes like the type VE10.
The type TV75 (or TV74) is the cheapest model of our breathers: its top flange is made in corrosion proof aluminium alloy.
The silicagel housing is made of cellulose triacetate (cellidor by Bayer), suitable for mineral oil; only upon request, this
breather can be fitted with a stainless steel cylindrical protection.
File : ACCESSORI DISTRIBUZIONE UNCONTROLLED COPY REV 04 dtd 09/10/09