Zero-Cross

The term zero-cross or synchronous operation of SCR's is derived from the fact that the SCR's are turned on only when the instantaneous value of the sinusoidal waveform is zero.

In zero-cross operation power is applied for a number of continuous half-cycles and then removed for a number of half-cycles to achieve the desired load power in the same manner as power would be controlled with a mechanical switching device. 

Model Phases Firing Mode Output Current Low Current High Highlights
Multizone MicroFUSION Single phase Phase angle, Zero cross, Zero Cross Transformer Mode AC 8 400

MicroFUSION is an ultra-compact high-performance microprocessor-based power controller, available in single or three phase models to control AC loads. 

MicroFUSION Three Phase Three phase Phase angle, Zero cross, Zero Cross Transformer Mode AC 8 400

MicroFUSION is an ultra-compact high performance digital SCR controller that adapts to the analog environment as well as the digital environment.

MicroFUSION Single Phase Single phase Phase angle, Zero cross, Zero Cross Transformer Mode AC 8 400

MicroFUSION is an ultra-compact high performance digital SCR controller that adapts to the analog environment as well as the digital environment. 

FUSION Three Phase (AC) Power Controller Three phase Phase angle, Zero cross, Burst AC 50 1 200

24 - 600 Vac. A microprocessor-based SCR controller operating both analog and digital interfaces. A phase angle or zero cross fired SCR controller which linearly controls, with respect to the setpoint, the AC voltage, current, or true power applied to a three phase electrical load. The 3 phase controller can be ordered in either 2 or 3 leg control with 2 leg being limited to zero cross firing. Control is achieved for 3 leg by three pairs of inverse parallel SCRs or in 2 leg by 2 pairs of inverse parallel SCRs.

FUSION Single Phase (AC) Power Controller Single phase Phase angle, Zero cross, Burst AC 50 1 200

24 - 600 Vac. A microprocessor-based SCR controller operating both analog and digital interfaces. A phase angle or zero cross fired controller which linearly controls, with respect to the setpoint, the AC voltage, current, or true power applied to an electrical load. Control is achieved by means of a pair of inverse parallel SCRs.

Compact FUSION Three Phase Power Controller Three phase Phase angle, Zero cross, Burst AC 10 160

24 - 600 Vac. A microprocessor-based SCR controller operating both analog and digital interfaces. Can be ordered in either 2 or 3 leg control with 2 leg being limited to zero cross firing. Output is controlled linearly with respect to command signal and can be set to the average or RMS value of the voltage or current, as well as true instantaneous power or external feedback.

Compact FUSION - Single Phase Power Controller Single phase Phase angle, Zero cross, Burst AC 10 160

24 - 600 Vac. A microprocessor-based SCR controller, operating with both analog and digital interfaces. Output is controlled linearly with respect to command signal and can be set to the average or RMS value of the voltage or current, as well as true instantaneous power or external feedback.

3337 Three Phase Zero Cross Power Controller Three phase Zero cross AC 200 750

208 - 575 Vac. Three Phase, Zero Cross SCR Controller. Accepts most commands. Features include: Sync-guard, Trans-guard, shorted SCR detection and on-board line fusing for most frame sizes.

3037 Three Phase Zero Cross Power Controller Three phase Zero cross AC 85 750

208 - 575 Vac. Analog SCR Controller. Accepts most commands. Features include: Sync-guard, Trans-guard, Shorted SCR detection and on-board line fusing for most frame sizes.

3027 Three Phase Power Controller Three phase Zero cross AC 85 750

208 - 575 Vac. Analog SCR Controller. Accepts most commands. Features include: Sync-guard, Trans-guard and on-board line fusing for most frame sizes.

3021B Three Phase Power Controller Three phase Zero cross AC 10 70

120 - 575 Vac. Analog SCR Controller. Accepts most commands. Sync-guard smoothes out line current draw when multiple controllers are in use.

3021A Three Phase Power Controller Three phase Zero cross AC 10 70

120 - 575 Vac. Analog SCR Controllers. Accepts most commands.

3020 Three Phase Power Controller Three phase Zero cross AC 10 70

120 - 575 Vac. Analog SCR Controller. Powered off of the 4/20mA loop, so no control transformer is required.

1600 (Multi-zone) Power Controller Single phase Phase angle, Zero cross AC 10 70

120 to 575 Vac. Multi-zone SCR Controller. Accepts most commands. Allows mixing of line voltages and load currents for multiple zones in a small footprint.

1027A Single phase Zero cross AC 50 160

120 to 575 Vac. Analog SCR Controller. Accepts most commands. Features include: Sync-guard and Trans-guard.

1021B Single phase Zero cross AC 10 70

120 - 575 Vac. Analog SCR Controller. Sync-guard™ smoothes out line current draw when multiple controllers are in use.

1021A Single phase Zero cross AC 10 70

120 - 575 Vac. Analog SCR Controller. Accepts most commands.

1020 Single phase Zero cross AC 10 70

120 - 575 Vac. Analog SCR Controller. Powered off of the 4/20mA loop, so no control transformer is required.