The term Zero-Cross SCR's are turned on only when
the instantaneous value of the sinusoidal wave is zero. Power is
applied for a number of continuous half-cycles and then removed for a number
of half-cycles. 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 Three Phase, Zero-Cross requirements.
| MODEL | VOLTAGE | CURRENT | COMMAND |
|
APPROVAL |
| 3020
Specs |
120 to 575 | 10 to 40 & 70 | 4/20mA | Compact, 4/20mA Loop powered | UL Listed |
| 3021A
Specs |
120 to 575 | 10 to 40 & 70 | Most Commands | Compact | UL Listed |
| 3021B | 120 to 575 | 10 to 40 & 70 | Most Commands | Compact, Sync-Guard | UL Listed |
| 3023 | 120 to 575 | 10 to 40 & 70 | 4/20mA | Compact, Time Proportioned, 4/20mA Loop powered | UL Listed |
| 3024
Specs |
120 to 575 | 10 to 40 & 70 | 3 to 32 Vdc | Compact | UL Listed |
| 3024A
Specs |
120 to 575 | 10 to 40 & 70 | 90 to 280 Vac | Compact | UL Listed |
| 3027
Specs |
120 to 575 | 85 to 1000 | Most Commands | Sync-Guard, Trans-Guard | UL Listed to 425 Amps |
| 3031 | 120 to 575 | 10 to 40 & 70 | 1 to 5 Vdc & Pot. | Compact | UL Listed |
| 3037
Specs |
208 to 575 | 85 to 750 | Most Commands | Shorted SCR Detection | UL Listed to 425 Amps |
THREE LEG CONTROLLERS
| MODEL | VOLTAGE | CURRENT | COMMAND | FEATURES | APPROVAL |
| 3320 | 120 to 575 | 10 to 40 & 70 | 4/20mA | Compact, 4/20mA Loop powered | UL Listed |
| 3321A | 120 to 575 | 10 to 40 & 70 | Most Commands | Compact | UL Listed |
| 3324 | 120 to 575 | 10 to 40 & 70 | 3 to 32 Vdc | Compact | UL Listed |
| 3337 | 208 to 575 | 200 to 600 | Most Commands | Shorted SCR Detection | - |