SCR19-H

Supported Applications

The Omega SCR19-H and SCR39-H Series power controllers are designed to proportion electric power to resistive loads only. Documented applications include ovens, furnaces, and heat sealers. These solid-state units consist of SCRs (silicon-controlled rectifiers), properly sized heat sinks, trigger circuitry, and fuses supplied on panels for surface mounting.

The controllers accept a 4 to 20 mA dc output from a temperature controller. They are not designed to drive transformers or any inductive load.

Operating Conditions & Performance

Performance specifications define the operational envelope for these fan-cooled units:

• Supply Voltage: 120 to 600 Vac
• Frequency: 50 to 60 Hz
• Current Rating: 125 to 250 A
• Ambient Temperature: 0 to 50°C (32 to 122°F)
• Cooling Requirement: Fan cooled, requires 120 Vac control voltage
• Input Control Signal Isolation: 2500 Vac
• Transient Voltage Protection: Inherent built-in immunity

The series features diagnostic LED indicators for shorted or open SCR conditions and includes semiconductor I²T fusing.

Variants by Load Configuration

• SCR19Z-H: 1-phase, 1-leg control (Zero-Voltage Switching)
• SCR39Z-H: 1-phase, 2-leg control for 3-wire delta or 3-phase ungrounded wye
• SCR19P-H: 1-phase, 1-leg control (Phase-Angle Firing)
• SCR39P-H: 3-phase, 3-leg half control for 3-wire delta or 3-phase ungrounded wye

Configuration Options

The series offers configurable options across line voltage, current load, and firing methods. Model numbers follow the pattern: [Series]-[Line Voltage Code]-[Current Load (A)]-[Soft Start or Voltage Limit].

Line Voltage Codes

• 12: 120 Vac
• 20: 208 Vac
• 24: 240 Vac
• 48: 480 Vac

Firing Methods and Options

The series supports Zero Crossing (Z) or Phase-Angle Fired (P) configurations. Phase-angle models may include soft start or voltage limit options to extend heater life by reducing thermal shock:

• S9: Soft start 9 seconds
• S15: Soft start 15 seconds
• S30: Soft start 30 seconds
• S60: Soft start 60 seconds
• S120: Soft start 120 seconds
• V: Voltage limit

Maintenance and Replacement Parts

The controllers are described as having no maintenance due to all solid-state components. Replacement fuses are available for the series (120 to 480 Vac):

• SCR-210A044U01: 125 A fuse
• SCR-210A046U01: 200 A fuse
• SCR-210A045U01: 250 A fuse

Note: When fuses are added to the unit, add 83 mm (3.3") to height.

Key Product Differences

The series is divided into two primary physical form factors with distinct dimensions and weights:

• SCR19-H / SCR19P-H Series: 222.25 mm (8.750 in) height, 135.12 mm (5.320 in) width, 370.84 mm (14.6 in) depth.
• SCR39Z-H Series: 222.25 mm (8.750 in) height, 287.02 mm (11.3 in) width, 370.84 mm (14.6 in) depth.
• SCR39P-H Series: 222.25 mm (8.750 in) height, 394.46 mm (15.530 in) width, 370.84 mm (14.6 in) depth.

Weight varies by model and current rating; for example, SCR19P-H models range from 6.1 kg (13.5 lb) to 6.4 kg (14.0 lb), while SCR39Z-H models weigh approximately 12.5 kg (27.0–27.5 lb).

OMEGACARE™ extended warranty program is available for these models, covering parts, labor, and equivalent loaners.