When do you use low scale burn out?
An old power station was having a problem with frequent boiler trips due to old thermocouples going open circuit. If the thermocouple went open circuit the boiler would automatically trip. The power plant instrumentation was old and had upscale burn out temperature transmitters. As there were 12 boilers on the plant it was decided to shut each unit down and replace the 128 thermocouples within the next 6 months. The cost was very extreme.
The problem was discussed with a Datexel Sales Engineer and he suggested replacing the temperature transmitters with PC programmable DAT1065 which could be set up to have a down scale burn out. The power station manager was informed and the change was implemented, resulting with two benefits.
The two benefits
1 The plant did not have to be shut down to replace the thermocouple as only the transmitters needed to be replaced.
2 When a thermocouple went open circuit it gave a low temperature reading and the plant did not trip.
This allowed the plant to continue to run and the thermocouples were then replaced on a normal scheduled shut down.
The DAT 1065 is an isolated temperature transmitter from Datexel. It is PC programmable that can be configured to convert thermocouples (J, K, S, R, B, E, T, and N types), RTD (Pt100, Pt1000, Ni100 and Ni1000), voltage (mv 0-700mV and Voltage 0-10V) potentiometer (200 Ohms, 500Ohms and 50Kohms), resistance (0-300 and 0-2000Ohms) current (-10mA to +24mA) to 4-20mA. The unit is loop powered and is able to drive impedance to 1000 Ohms.