SCR Power Controls
SCR Power Controls are zero-cross fired or phase angled fired, and ideal for the control of pure resistant loads that can accommodate rapid, full power, ON-OFF cycling. Zero-crossed fired SCR's do not create RFI (radio frequency interference) and will not adversely affect sensitive electronic equipment, like logic controllers, computers, other SCR controllers) located in the same building or area. SCR Power Controls are protected from line voltage transients, making them more reliable in a variety of applications. Aero-cross fired SCR's when coupled with PID or Time proportioning controllers operate in a series of full ON-OFF cycles known as time proportioning burst firing.
The time proportional control accepts the control output signal and converts it into a time firing. The time proportional signal determining the amount of ON time and OFF time per duty cycle. The continuous, high repetitious rate of full ON and full OFF cycles produces a smooth power output to the load (heater) and stabilizes temperature. SCR Power Controls differs from other switches in fast action. For example, while a contactor may cycle 2 times per minute, a SCR may cycle approximately once per second. The fast SCR cycle time results in a final temperature much closer to the desired set point and reduces energy costs. SCR Power Controls modulates small increments of power to the load, unlike traditional mechanical control, and eliminates the overshoot and undershoot associated with a load controlled by a contactor.
SCR Power Controls Features:
Voltage: 48 to 600 volts
Phase: single (1) or three (3)
Current: 15 to 700 Amps
Control Input: 1 = 0 to 5 Volts DC, 2 = 0 to 10 volts DC, 3 = 4 to 20 mAmps, 4 = 0 to 135 Ohms
Controlled Lines: three phase 2 or 3 lines
Control Output: zero cross fired = Z P = phase angle fired