| Command Signal
|4 - 4/20 mA
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.
The standard control transformer has three user selectable voltage taps: 240, 480 & 575 VAC, 50/60 Hz.
Peak Forward and Reverse Voltage:
SCR Surge Current Ratings (peak one cycle non-repetitive ITSM @ 125°C):
| Controller Rating
||Surge Current Rating
|50 & 80 Amp:
||1750 Amps Peak
||1900 Amps Peak
||4000 Amps Peak
||4500 Amps Peak
||5200 Amps Peak
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.
Output can be selected to be proportional to either the run command or the idle command by remote contacts.
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.
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.
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.
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).
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.
1.5 Watts per amp of load current, per phase.