| Command Signal |
Input Impedance |
| 4 - 4/20 mA |
300 ohms |
If it is desired to use a current command in both the run and idle command input, the signals must either be common sourcing, or they must be isolated from one another.
Operating Voltage: The standard control transformer has three user selectable voltage taps: 240, 480 & 575 VAC, 50/60 Hz.
Peak Forward and Reverse Voltage: 1400V.
SCR Surge Current Ratings (peak one cycle non-repetitive ITSM @ 125°C):
| Controller Rating |
Surge Current Rating |
| 50 & 80 Amp: |
1750 Amps Peak |
| 20 Amp: |
1900 Amps Peak |
| 160 Amp: |
4000 Amps Peak |
| 200 Amp: |
4500 Amps Peak |
| 250 Amp: |
5200 Amps Peak |
SCR Protection: dV/dT rating = 200 volts/microsecond. dV/dT circuit consists of a capacitor in series with a noninductive resistor. This circuit is in parallel with the SCRs. the SCRs are protected from voltage transients by a Metal Oxide Varistor.
Run/Idle Control: Output can be selected to be proportional to either the run command or the idle command by remote contacts.
Electrical Connections: Connectors for line and load are provided for copper wire from 6 ga to 250 MCM on controllers rated 50 to 425 Amps. Connectors for line and load are provided for copper wire from 1/0 to 500 MCM on controllers rate 500 to 750 Amps.
Electrical Isolation: Heatsink to supply and load voltage: 2500 Volts peak. Command signal to supply and load voltage: 1500 Volts peak.
Zero and Span: Potentiometer on the circuit board allow zero and span adjustments of ±25% of span for run and idle.
Current Limiting: A potentiometer on the circuit board allows adjustment of the current limit setting from 20% to 105% of the controller rating. (The current limit potentiometer is factory set for 105% of the rate current less otherwise specified.)
Voltage Meter Output: A filtered metering signal equals 4.8 VDC when the nominal line voltage is applied to the load. Metering load = 5 mA max.
Current Meter Output: A filtered metering signal equals 5.0 VDC when the frame rating current is applied to the load. Metering load = 5 mA max.
Gate Drive: An optically coupled current source of 250 mA with a minimum compliance of 10 volts provides the gate drives to the SCRs. Duration of "back porch" is approximately 1.4 milliseconds (60 electrical degrees).
Voltage Compensation: When using voltage feedback, the load voltage remains constant, independent of supply voltage changes within +10%, -15%.1.5 watt per amp of controlled current.
Power Dissipation: 1.5 Watts per amp of load current, per phase.