SINGLE PHASE, ZERO CROSS

The term Zero-Cross (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 wave 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. The frequency of the on-off cycles can be extremely fast because there is no limit to the number of switching operations the SCR can perform.

The following models are suited for applications with Single Phase, Zero-Cross requirements.
 
MODEL
FEATURES
COMMAND
VOLTAGE
CURRENT
APPROVAL
1020
Specs
4/20 mA Loop Powered
4/20mA Only
120 to 575Vac
10 to 40 & 70 Amps
UL Listed
1021A
Specs
Compact Most Commands 120 to 575Vac 10 to 40 & 70 Amps UL Listed
1021B
Specs
Sync-Guard Most Commands 120 to 575Vac 10 to 40 & 70 Amps UL Listed
1023
Specs
Time proportional & 4/20 mA Loop Powered 4/20mA Only 120 to 575Vac 10 to 40 & 70 Amps UL Listed
1024
Specs
On-off control 3 to 32 Vdc
90 to 280V ac
120 to 575Vac 10 to 40 & 70 Amps UL Listed
1026
Specs
On-off control
120Vac or 240Vac
120 to 575Vac
10 to 40 & 70 Amps
 
1024A
Specs
On-off control 90 to 280 Vac 120 to 575Vac 10 to 40 & 70 Amps UL Listed
1027A
Specs
Sync-Guard, Trans-Guard & Line Voltage Compensation Most Commands 120 to 575Vac 50 to 750 Amps UL Listed
1031
Specs
Adaptable to 'Run/Idle' Configuration 1 to 5 Vdc & Pot. 120 to 575Vac
10 to 40 & 70 Amps
UL Listed
1037A Shorted SCR Detection Most Commands 120 to 575Vac
50 to 750 Amps
UL Listed

Single Phase, Phase Angle
Three Phase, Phase Angle       Three Phase, Zero Cross
Special Controllers & Accessories
DIN-Pak Solid State Relay

McGoff-Bethune, Inc.
5970 Unity Drive Suite A
Norcross, GA 30071
770-840-9811    800-303-4705     Fax: 770-840-7514
sales@mcgoff-bethune.com
 www.mcgoff-bethune.com