Watlow Solid State Relays

Solid State Relays Watlow solid state relays (SSR) offer many of the advantages of solid state power controllers, but at a lower cost. Watlow's extensive knowledge in power controller design led to the development of a special fast cycle input card that enables a solid state relay to operate from a standard 4-20mA instrumentation command signal. Test results show that zero-cross solid state relays in combination with the fast cycle card promote better temperature control and longer heater life than slow cycle relays. Through a time proportional cycle rate of 1⁄10 of a second, heater life will be extended. Both low and high voltage solid state relays are available from 24 to 660VAC. All ac output models include back-to-back silicon controlled rectifiers (SCRs) for a more rugged design than the traditional triac-based solid state relay. The internal design allows it to tolerate high currents and harsh electrical environments of heavy industry. Watlow also offers a switched VDC model for dc heating applications. Watlow provides all of the components necessary for trouble-free operation. This includes two standard convenience items: a thermal foil to ensure proper thermal transfer from the relay to the heat sink and belleville washers to ensure that the relay is mounted with sufficient pressure to enable good heat transfer. Matched semiconductor fuses and heat sinks are available to complete the power switching package.

• Fast cycle card increases heater life, optimizes temperature control and accommodates higher watt density heaters
• Zero cross firing for minimal electrical noise
• Back-to-back SCR design withstands harsh or hostile industrial environments
• Meets applications requiring agency approval

Series CZR The SERIES CZR solid state relay provides a low-cost, highly-compact and versatile solid state option for controlling electric heat. With DIN-rail and back panel mounting standard on every controller, the CZR solid state relay allows for simple and quick installation. The extensive capabilities of the SERIES CZR include single-phase, 18 to 42 ampere zero-cross switching up to 600VAC (see output rating curve). It's unique integrated design removes the guess work associated with selecting a proper heat sink and precise terminations for the application. This solid state relay controller holds many agency certifications and is ideal for applications that require UL®, CSA and CE approvals. The SERIES CZR is available in VAC/VDC input contactor versions and all configurations are model number dependent and factory selectable.

• DIN-rail or standard panel mount for versatile, quick and low-cost installation
• Compact size reduces panel space and cost
• Touch-safe terminals increases installer and operator safety
• Mercury free for environmental safety
• Faster switching with solid state saves energy and extends heater life

Contact a Thermal Devices' Sales Engineer for more information! Or, request a quote