GE IS200VTCCH1CBB Thermocouple Processor Board

FUNCTIONAL DESCRIPTION:

IS200VTCCH1CBB is a Thermocouple Processor Board manufactured and designed by General Electric as part of the Mark VI Series used in GE Speedtronic Control Systems. The Thermocouple Input (VTCC) board accepts 24 thermocouple inputs. These inputs are wired to the TBTC or DTTC terminal boards. Cables with molded plugs connect the terminal board to the VME rack where the VTCC thermocouple processor board is located. The TBTC can provide both simplex (TBTCH1C) or triple module redundant (TMR) control (TBTCHIB). Two groups of the VTCC provide different temperature ranges optimized for gas turbine control applications (VTCCH1) and general-purpose applications (VTCCH2). The same terminal boards are used with both groups of the VTCC.

VTCCH1 supports E, J, K, S, and T types of thermocouples and mV inputs. The mV span is -8 mV to +45 mV.
VTCCH2 supports E, J, K, S, and T as well as B, N, and R types of standard thermocouples and mV inputs. The mV span for VTCCH2 is -20 mV to +95 mV.

INSTALLATION:

Power down the VME processor rack
Slide in the VTCC board and push the top and bottom levers in with your hands to seat its edge connectors
Tighten the captive screws at the top and bottom of the front panel
OPERATION:Type E, J, K, S, and T thermocouples can be used with VTCCH1, and they can be grounded or ungrounded. Type E, J, K, S, T, B, N, and R thermocouples can be used with VTCCH2, and they can be grounded or ungrounded. They can be located up to 300 m (984 ft) from the turbine control cabinet with a maximum two-way cable resistance of 450 Ω. High-frequency noise suppression and two cold junctions (CJ) reference devices are mounted on the terminal board. Linearization for individual thermocouple types is performed in software by VTCC. A thermocouple that is determined to be out of the hardware limits is removed from the scanned inputs to prevent adverse effects on other input channels.COLD JUNCTIONS:If both CJ devices are within the configurable limits, then the average of the two is used for CJ compensation. If only one CJ device is within the configurable limits, then that CJ is used for compensation. If neither CJ device is within the configurable limits, then a default value is used. The thermocouple inputs and cold junction inputs are automatically calibrated using the filtered calibration reference and zero voltages.