Continuous Monitoring of Low Voltage Transformers

Intent:

• The thermal monitor is the latest technology, replacing hinged doors and IR windows to provide a continuous thermal monitoring solution.

• Loose electrical connections at the coil taps and the transformer terminals allow contamination to get between current carrying parts. These dirty and/or loose connections increase the resistance, causing the temperature of the connection to exceed the thermal rating of the cable insulation.

• System specifically designed to provide continuous, predictive monitoring of low voltage transformer connection.

  Features:

• Identifies cable connection whose temperature exceeds the 194°F (90°C) required rating of cable insulation, which can cause a malfunction due to insulation overheating.
• Visible LED lights, allowing monitoring by end users 24/7. This is an improvement over the “snap shot” obtained during annual inspection or IR scans by service personnel.
• Option to connect to monitoring software via RS-485.
• Relay outputs (Normally Closed or Normally Open) allows connection of device to external circuit, such as a warning device (lights, klaxon, etc.) or a shunt trip primary circuit breaker for shutting down the transformer when a hot spot is detected.
• Provides thermal monitoring of the incoming, outgoing, and factory power connection points.

Top Mounted:

• Mounted on the top of the DOE 2016 EX product offering, minimizing the impact of floor space required for the transformer installation.

  NOTE: No impact on ceiling mounting bracket clearance for support rods.
  Inside the Enclosure:

• Overcurrent protection
• dc power supply
• Two data cards

  • Monitoring H1, H2, H3, X1, X2, X3

  • Monitoring tap jumpers (six locations)

  Reset button
• LED monitor two types of connections
  • Terminals (H1, H2, H3, X1, X2, X3) input/output power
  • Tap Jumpers-loose and/or dirty tap jumpers are a main source of overheating.

• Quick connect thermal couple-routed via two access points in the bottom

  Front View of the Thermal Monitor Enclosure

• LEDs glow green when the temperature is below the UL® 194°F (90°C) requirement on the thermal couples.

• LEDs flash red when temperature exceeds 194°F (90°C); the temperature point can be specified by customer if the factory setting is not acceptable.

  Inside the Transformer:

• Factory-installed thermal couples are connected to incoming and outgoing landing pads (H and X terminals) and tap jumper leads at the coil and the terminals.

• Cables are routed so that they will not interfere with customer connections and wire bending radius or side access.

Recommended text to add to specification:

Bolted electrical connections shall be monitored for high resistance via thermo couples connected to monitoring device for continuous survey. Set at 194°F (90°C) with a LED indicators on the transformer green for operating within design parameters, and flashing red when exceeding those parameters.