Liquid Sensing & Oil Transformer

Our Thermostat Model ITD is the best suited thermal overload protector for sensing temperature of liquids and for over temperature and burnout protection of Oil Transformers.

Thermostat for sensing temperature of Liquids – Model ITD

Description of Thermostat

Model ITD has been designed by our engineers after extensive R&D for sensing the temperature rise of liquids as well as for over temperature protection of Oil Transformers. It has a solid machined brass body with a 1/4″ BSP threading so that it can be screwed on to any liquid tank or oil tank. The brass body provides greater strength as well as better heat sensing capability. The operating principle is based on the over center mechanism which operates a snap action bimetal and a beryllium copper switching blade. The normal snap action disc thermostats have a delayed restart and the trip temperature drifts downwards, while in our thermostats, due to the over center mechanism, the restart is quick and the trip temperature remains stable, even after continuous usage. The bimetal strip inside senses the temperature rise and snap opens the contacts. The contacts are made of solid silver for long life. All the internal components are spot welded on a stainless steel housing. The brass body is electrically insulated, so there is no chance of any electrical shock. The body is double sealed, so it is not affected by dust, moisture, etc. This thermal overload protector is available in Normally Open (N.O.) or Normally Closed (N.C.) contacts.

Special Features:

  • Solid brass body for strength
  • Better heat sensing capability
  • Available with Normally Open (N.O.) or Normally Closed (N.C.) contacts
  • 1/4″ BSP threading for easy mounting
  • Solid silver contacts for long life of 1,00,000 operations
  • Snap action bimetal thermostat
  • Teflon insulated lead wires
  • Available in any temperature from 50C to 160C

Application of Thermal Overload Protector

Model ITD needs to be screwed in to the liquid filled tank or oil tank so that it can sense the temperature of the liquid or oil. This thermostat should be screwed in where the liquid becomes hot as this will enable it to accurately sense the temperature rise. When the liquid heats up, it will sense the temperature rise and the contacts will snap open, which will trip off the thermostat, thereby, disconnecting the equipment or transformer and saving it from burning out.

If the equipment has a low ampere load of up to 6 to 8 amps, the thermostat can be connected directly in series with the equipment. When it trips off, it will also switch off the equipment. Upon cooling, the thermostat will restart and will restore supply to the equipment.

In the case of oil filled transformers, the two Teflon lead wires should be connected to a relay or a contactor because the thermostat cannot be connected directly in series with an oil filled transformer as it cannot withstand the high ampere load. The relay or contactor can be used to provide an indication, such as a light or alarm, or switch on a cooling circuit or operate a control circuit when the liquid or oil overheats. Please consult us for proper technical guidance.

 Voltage Up to 250VAC or 24VDC
 Continuous Load Up to 8 AMPS
 Maximum Load Switching Capacity 30 AMPS
 Contacts Configuration Available with Normally Open (N.O.) or Normally Closed (N.C.) contacts
 Switching Action SPST Normally Closed (N.C.) or Normally Open (N.O.) contacts which open or close with a snap action at a  preset temperature and will disconnect the power supply to the Liquid Monitoring Equipment or the Oil Transformer.
 Flash-over Voltage Exceeds 2 KV between body & leads.
 Endurance (Life) Exceeds 100,000 operations (trippings).
 Trip Temperature Available preset for any trip temperature between 50 ± 5 C to 160 ± 5 C specified by customer. Trip temperature not adjustable.
 Reset Temperature Reset temperature (restart temp) approx. 15 ± 5 C below trip temperature.
 Restart Mode The thermostat/thermal overload protector will automatically restart upon cooling will restore power supply to the Liquid Monitoring Equipment or the Oil Transformer.
 Fitting or Mounting The outer body of the thermostat/thermal overload protector has 1/4″ BSP threads so that it can be screwed in to a liquid or oil tank.
 Connections For low amps application, the thermostat/thermal overload protector can be connected in series with the heat source. For higher amps. application it needs be connected to a control circuit, relay, contactor, etc., which can provide an indication of overheating and thereafter, switch off the equipment when the thermostat trips off.

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