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SwitchLITE Model EZT



Description
The SwitchLITE Model EZT, a UL 1008 listed Automatic Transfer Switch for Emergency Lighting Applications, allows dimmable lighting fixtures to function as essential emergency lighting. The Model EZT (Emergency Zone Transfer Cabinet) is designed to automatically transfer up to eight (8) branch circuits to emergency power when normal power fails, and then back to normal power once it has been restored.

Upon transfer to emergency power, lighting fixtures that are dimmed or off are brought to full illumination to provide safe egress.

The Model EZT accommodates 4, 6 or 8 individual 20 amp branch circuits, and is ideal for use in a dimmer rack application (see illustration)



Features & Benefits
Technical Specs
Applications
FAQ



General Specifications


Guide Specifications


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Features & Benefits

  • Soft Start Control with user-selectable 0 to 2 second voltage ramp to accommodate the high inrush current associated with energizing certain types of lighting fixtures.
  • User-Adjustable Transfer Delay to and from emergency power to best fit specific applications.
  • Remote Command Transfer (RCT) allows external contact(s) to initiate the automatic transfer of all circuits from normal to emergency power during critical NFPA-mandated test periods.
  • The RCT input may connect to a Controlled Power Company emergency lighting inverter’s “test active” contact to initiate the transfer of emergency circuits.
  • As the Controlled Power lighting inverter automatically performs and logs NFPA-mandated tests, all emergency lighting loads are energized to validate system testing.
  • A local keyed test switch is provided to simulate a power failure during manual testing of the emergency lighting and life safety system.


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Technical Specs

  • Branch Circuit Voltage: 120 VAC or 277 VAC or 347 VAC, 60 hertz
  • Branch Circuit Amperage: Rated for 20 amps maximum each circuit, internally fused
  • Number of Branch Circuits: 4, 6 or 8 individual circuits
  • Branch Circuit Configuration: Standard 2 wire plus ground, or 2 wire plus ground with an optional low voltage or line voltage ballast control signal
  • Single Phase Voltage Sensing of Normal Power Source: 120 VAC, 277 VAC, or 347 VAC (1 wire plus neutral); or 240/120 VAC or 208/120 VAC (2 wire plus neutral)
  • Three Phase Voltage Sensing of Normal Power Source: 208 VAC, 480 VAC, or 600 VAC (3 wire plus neutral)
  • Emergency Power Input Circuit Breaker Required: 60 amp maximum, 1 pole
  • Undervoltage Automatic Transfer: User-selectable at -20% or -50% from normal power nominal voltage
  • Adjustable Transfer Delay: Transfer to emergency power 0 to 9 seconds; Transfer from emergency power back to normal power 0 to 15 minutes
  • Soft Start Control: User-selectable 0, 0.5, 1.0, or 2.0 seconds voltage ramp
  • Operating Temperature: 0°C to 40°C (32°F to 104°F)
  • Listed to UL 1008 Transfer Switch Equipment, Automatic Transfer Switch for Emergency Systems, 10,000 amp SCCR rating
  • C-UL Listed to CSA Standard C22.2 No. 178.1, Automatic Transfer Switches


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Applications

  • Theaters / Concert Halls
  • Worship Facilities
  • Conference Centers
  • Auditoriums
  • Restaurants
  • Banquet Halls
  • Casinos
  • Sports Facilities



  • What is a UL 1008 listed automatic transfer switch?

  • It is an electrically operated and mechanically held switch designed to safely transfer power between two (2) separate sources.



  • Are a UL 924 load control relay and a UL 1008 automatic transfer switch basically the same device?

  • No. A UL 924 listed load control relay is designed to shunt (bypass) around a local control device, such as an on/off switch, dimmer switch, or occupancy sensor. In comparison, a UL 1008 listed automatic transfer switch is designed to transfer between two (2) separate power sources, typically normal power and emergency power.



  • Can all UL 1008 listed automatic transfer switches be used in a “life safety application”?

  • No. UL 1008 has two (2) categories. Category WPWR covers automatic transfer switches for use in “Emergency Systems” that are essential for life safety, as defined in NEC Article 517, Health Care Facilities, and Article 700, Emergency Systems. This UL category also covers automatic transfer switches used as part of a “Legally Required Standby Systems”, Article 701. If not powered, the loads in legally required standby systems could create hazards to people or impede workers responding to an emergency event. In comparison, UL Category WPXT covers automatic transfer switches for Use in “Optional Standby Systems” not essential for life safety, as defined in NEC Article 702. Automatic transfer switches listed under this category have not been tested or listed for use in life safety applications.



  • Have all UL 1008 listed automatic transfer switches been put through the same reliability testing?

  • This is a very good question. UL 1008 testing requirements have changed over the years, becoming much more rigorous and demanding. Here are some of the current UL 1008 testing requirements. Any manufacturer of a UL 1008 listed automatic transfer switch to be used within an emergency system should be able to verify that their product passed each of these critical tests. Ask them! Overload Test: 300% load at .45pf – 50 switches (sources 180 degrees out of phase) – no welding of contacts can occur. Endurance Test 1: 200% load at .75pf – 3000 switches (sources 180 degrees out of phase) – no breakage or welding of contacts. Endurance Test 2: 100% load at .75pf – 3000 switches (sources 180 degrees out of phase) – no breakage or welding of contacts.



  • Is the Model EZT compatible with all types of light fixtures?

  • Yes. Fixture types include, but are not limited to LED, magnetic fluorescent ballasts, incandescent lamps, and electronic and high power factor fluorescent ballasts.



  • Why does the Model EZT have a “Remote Command Transfer (RCT)” input and how is it used?

  • The Model EZT’s Remote Command Transfer (RCT) input was designed to interface with external “normally closed” signal or alarm contacts. These contacts may originate from the fire alarm panel, multiple circuit breakers having auxiliary contacts, or the designated emergency power equipment. An automatic transfer from normal to emergency power may be initiated via one or more remote isolated dry-type contacts in series. The contacts will remain closed under normal conditions and open to initiate the transfer to emergency power. Emergency power will continue to feed lighting circuits when any remote contact is open, and reconnect to normal power when all remote contacts are closed. This feature ensures that the emergency lights are on and fully illuminated during NFPA-mandated test periods, or if the emergency situation does not coincide with a loss of power to the normal power source being monitored by the EZT.



  • Can the Model EZT be used with either an emergency lighting inverter or a standby generator as the emergency power source?

  • Yes. A Controlled Power Company centralized emergency lighting inverter is a true uninterruptible power source and is ideal in this application. A normally closed “test in progress” contact from the inverter is connected to the Model EZT’s Remote Command Transfer (RCT) input (explained in the FAQ answered above). This contact will open during NFPA mandated test periods and the designated emergency lighting circuits will be automatically transferred from normal to emergency power. In a standby generator application, the emergency lighting circuits will experience a momentary loss of power, dictated by the time it takes for the emergency generator to come on line. To ensure that emergency lighting circuits are transferred from normal to emergency power during NFPA mandated tests, the Model EZT’s RCT input may be connected to a normally closed contact that opens when the facility’s ATS has transferred generator power to the normal/emergency power panel.



  • Why does the Model EZT include an adjustable transfer delay feature?

  • User-adjustable settings are provided to control the transfer time to and from emergency power. The transfer to emergency power is adjustable from 0 to 9 seconds. Some users may prefer a small delay, so not to react to momentary outages only lasting a second or two. The transfer from emergency power to normal power is adjustable from 0 to 15 minutes. If HID fixtures are being used for general lighting in the public space…this extended delay keeps the emergency lights on during the time it takes for HID fixtures to regain their full illumination.



  • Why does the Model EZT include a soft start control feature?

  • The Model EZT’s soft start control is included to accommodate the high inrush current associated with energizing some types of emergency lighting fixtures. User-selectable settings from 0 to 2 seconds are provided to ramp on emergency power to all circuits. This control assures compatibility with various lighting fixture types and the emergency power source. If the designated emergency lights are dimmed or off at the time of a power outage…the emergency power source would otherwise see a significant current surge when these lights are transferred to emergency power. The EZT’s soft start control minimizes this surge and prevents it from affecting circuit breakers or overload settings.



  • How would I use the Model EZT’s optional auxiliary Form C contacts for ballast control applications?

  • Certain types of light fixtures can be controlled using either a low voltage (0-10V) or line voltage ballast control signal. In addition to the normal power source feeding the fixture, a separate connection is made to the ballast. This connection is to a variable voltage source which may dim the light, or simply turn it on/off. Such control may be used in daylight harvesting applications. This variable voltage source may be wired though the EZT’s form C auxiliary contacts in a way that applies a “full on” signal when a power outage occurs. Auxiliary contacts are provided for each branch circuit. To accommodate line voltage ballast control applications, emergency line voltage is available via a hardwired terminal, located next to each set of auxiliary contacts.