Watlow POWER SERIES Controllers
Microprocessor-Based SCR Power Controller Designed for Application Flexibility
For over thirty years Watlow® has been manufacturing solid state power controllers. Watlow's new POWER SERIES represents the latest in SCR power controller technology. This microprocessor-based product offers features and application flexibility unmatched by any other SCR power controller on the market today.
Capabilities include single-phase and three-phase models from 65 to 250 amps. Field configurable phase angle or zero-cross firing improves application flexibility on site where you need it. 50/60Hz independent operation means you can operate almost everywhere in the world without special calibration considerations. Serial communications utilizing Modbus® protocol allow for remote control setup, and monitoring of load status from a nearby computer station or control room.
On-board semiconductor fusing improves reliability by protecting the SCRs from heater short circuits. Plus, on-board heater bakeout and control diagnostics can help eliminate initial start up problems. All this in a touch-safe package that can be quickly and easily mounted in your control cabinet.
Agency approvals ensure a product that meets world safety and operational standards.
Features Benefits
Microprocessor-based technology Extremely versatile, field configurable
Snap-fit on a pre-mounted plate Easy installation
Models 65 through 250 amp ratings Handles a wide range of loads
Adjustable soft start Application flexibility
Heater and control diagnostics capabilities Monitor actual heater and control performance
Electrically touch-safe package Increased safety for installer and users
Serial comm with Modbus® RTU protocol Computer control and/or monitoring
Multi-zone capability Application flexibility, reduced panel space
Applications
Semiconductor processing
Plastics processing
Heat treating
Drying ovens
Food processing
Petroleum/chemical
Lighting equipment
Furnace/oven
Sords Electric
Showing posts with label ampere. Show all posts
Showing posts with label ampere. Show all posts
Friday, June 26, 2009
Wednesday, May 20, 2009
Solid State Relays ~ Fast switching
Sords Electric sells Solid State Relays (SSR) by Carlo Gavazzi.
A Solid State relay( SSR ) is an electrical switch that opens and closes under the control of another electrical circuit. A solid state relay( SSR ) is a solid state electronic component that provides a similar function to an electromechanical relay but does not have any moving components, increasing long-term reliability. With early SSR's, the tradeoff came from the fact that every transistor has a small voltage drop across it. This voltage drop limited the amount of current a given SSR could handle. As transistors improved, higher current SSR's, able to handle 100 to 1,200 amps, have become commercially available.
A solid state contactor is a very heavy-duty solid state relay, including the necessary heat sink, used for switching electric heaters, small electric motors and lighting loads; where frequent on/off cycles are required. There are no moving parts to wear out and there is no contact bounce due to vibration. They are activated by AC control signals or DC control signals from Programmable logic controller (PLCs), PCs, Transistor-transistor logic (TTL) sources, or other microprocessor and microcontroller controls.
Solid-state relays ( SSR's ) control load currents through solid-state switches such as triacs, SCRs, or power transistors. These elements are controlled by input signals coupled to the switched devices through isolation mechanisms such as transformers, reed relays, or optoisolators. Some solid-state relays also incorporate snubber circuits or zero-crossing detectors to reduce spikes and transients generated by interrupting load current. Since semiconductor switches can dissipate significant amounts of power, solid-state relays must generally be heat sinked to minimize operating temperature.
SSRs generate heat because of the voltage drop present in all semiconductor devices. A 40-A relay, for example, typically drops 1.2 V during conduction and, thus, dissipates 50 W of heat. However, SSR heat generation generally does not require special system design. These devices usually mount on circuit boards or control panels containing other semiconductor devices. Cooling and heat-sinking methods used for these devices are likely to be adequate for the SSR.
Some SSRs designed for controlling ac loads incorporate a zero-voltage turn-on circuit that switches the load on or off only when the power-line sine wave passes through zero. Highly capacitive loads such as lamps and heaters which produce high inrush currents at turn on generate little electromagnetic interference if actuated when line voltage is zero. However, inductive loads such as motors and transformers can saturate during the first half cycle after turn on and produce maximum interference when switched on as line voltage passes through zero. Zero-voltage switches should not be used.
Carlo Gavazzi offers a comprehensive range of solid state relays (SSR’s) featuring direct copper bonding technology for increased life and reliability. SSR’s are used extensively in the plastics, packaging, food processing, and HVAC industries - primarily for temperature control. They are the logical replacement for mercury contactors.
Other applications include lighting and pump switching. Furthermore, many of our relays feature horsepower ratings making them suitable for controlling motorized dampers in HVAC control systems - where their long life and noise-free switching make them ideal replacements for mechanical contactors.
Carlo Gavazzi's range includes single phase relays up to 125 amps and 3 phase relays up to 75 amps. They are available with both digital and analogue inputs (4-20 mA or 0-10 V) Furthermore, we also offer a complete range of SSR's with a built-in heatsink.
A Solid State relay( SSR ) is an electrical switch that opens and closes under the control of another electrical circuit. A solid state relay( SSR ) is a solid state electronic component that provides a similar function to an electromechanical relay but does not have any moving components, increasing long-term reliability. With early SSR's, the tradeoff came from the fact that every transistor has a small voltage drop across it. This voltage drop limited the amount of current a given SSR could handle. As transistors improved, higher current SSR's, able to handle 100 to 1,200 amps, have become commercially available.
A solid state contactor is a very heavy-duty solid state relay, including the necessary heat sink, used for switching electric heaters, small electric motors and lighting loads; where frequent on/off cycles are required. There are no moving parts to wear out and there is no contact bounce due to vibration. They are activated by AC control signals or DC control signals from Programmable logic controller (PLCs), PCs, Transistor-transistor logic (TTL) sources, or other microprocessor and microcontroller controls.
Solid-state relays ( SSR's ) control load currents through solid-state switches such as triacs, SCRs, or power transistors. These elements are controlled by input signals coupled to the switched devices through isolation mechanisms such as transformers, reed relays, or optoisolators. Some solid-state relays also incorporate snubber circuits or zero-crossing detectors to reduce spikes and transients generated by interrupting load current. Since semiconductor switches can dissipate significant amounts of power, solid-state relays must generally be heat sinked to minimize operating temperature.
SSRs generate heat because of the voltage drop present in all semiconductor devices. A 40-A relay, for example, typically drops 1.2 V during conduction and, thus, dissipates 50 W of heat. However, SSR heat generation generally does not require special system design. These devices usually mount on circuit boards or control panels containing other semiconductor devices. Cooling and heat-sinking methods used for these devices are likely to be adequate for the SSR.
Some SSRs designed for controlling ac loads incorporate a zero-voltage turn-on circuit that switches the load on or off only when the power-line sine wave passes through zero. Highly capacitive loads such as lamps and heaters which produce high inrush currents at turn on generate little electromagnetic interference if actuated when line voltage is zero. However, inductive loads such as motors and transformers can saturate during the first half cycle after turn on and produce maximum interference when switched on as line voltage passes through zero. Zero-voltage switches should not be used.
Carlo Gavazzi offers a comprehensive range of solid state relays (SSR’s) featuring direct copper bonding technology for increased life and reliability. SSR’s are used extensively in the plastics, packaging, food processing, and HVAC industries - primarily for temperature control. They are the logical replacement for mercury contactors.
Other applications include lighting and pump switching. Furthermore, many of our relays feature horsepower ratings making them suitable for controlling motorized dampers in HVAC control systems - where their long life and noise-free switching make them ideal replacements for mechanical contactors.
Carlo Gavazzi's range includes single phase relays up to 125 amps and 3 phase relays up to 75 amps. They are available with both digital and analogue inputs (4-20 mA or 0-10 V) Furthermore, we also offer a complete range of SSR's with a built-in heatsink.
Tuesday, May 12, 2009
Mercury Contactors or Mercury Displacement Relays
Mercury contactors are a great way to switch industrial loads on and off. Mercury contactors or MDR's (Mercury Displacement Relays) can be the best option for electric heating elements. The Mercury relays have very long life, millions of cycles, are quiet and can be cycled up to once every second. Mercury Relays far outlast and out perform mechanical contactors and relays which can have only 100,000 cycles and be limited to switching once every 30 to 60 seconds. Normally closed mercury relays are also used for traffic control to control blinking lights as they have the long life and higher temperature resistance than other types of contactors, especially solid state relays.
Mercury Displacement Relays are all designed and built to meet the most exacting demands of industry. They have won their high place in the electrical field by doing the tough and tricky jobs that ordinary equipment could at best do in an uncertain manner. They have proved their ability to stand up under the most adverse conditions of temperature, dust and moisture, in all types of applications. All the care required for the manufacture of high-grade instruments is used in the manufacture of the switches. All switch parts are specially cleaned, and contamination is avoided by use of tweezers, gloves, etc., when making assemblies.
Contactors are hermetically sealed with high quality glass to metal seals.
The stainless steel tube is totally encapsulated in high grade UL approved epoxy to prevent moisture damage and voltage breakdown through the protective coating.
The coils are wound on compact nylon bobbins and molded onto the metal tube to provide minimum power loss. This allows for low coil power required to actuate the contactor. This also enables the units to handle high loads with minimum derating due to higher ambient temperatures.
Inert gases internally prevent excessive arcing between the mercury and the electrodes which enables the unit to function for millions of cycles with very low contact resistance, and minimum deterioration of the internal parts.
Available in all standard coil voltages, in single, two and three pole arrangements. Other coil voltages available upon request.
In multiple pole units each tube is actuated by its own coil. This eliminates pull-in variation between contact tubes, assuring consistent switching.
Contactors are hermetically sealed with high quality glass to metal seals.
The stainless steel tube is totally encapsulated in high grade UL approved epoxy to prevent moisture damage and voltage breakdown through the protective coating.
The coils are wound on compact nylon bobbins and molded onto the metal tube to provide minimum power loss. This allows for low coil power required to actuate the contactor. This also enables the units to handle high loads with minimum derating due to higher ambient temperatures.
Inert gases internally prevent excessive arcing between the mercury and the electrodes which enables the unit to function for millions of cycles with very low contact resistance, and minimum deterioration of the internal parts.
Available in all standard coil voltages, in single, two and three pole arrangements. Other coil voltages available upon request.
In multiple pole units each tube is actuated by its own coil. This eliminates pull-in variation between contact tubes, assuring consistent switching.
| FEATURES | |||||||||
|
Subscribe to:
Posts (Atom)