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Emergency EAC ISS, FT or 3FT Sizing or De-Rating

Should the Large (EAC ISS, FT, 3FT or Inverters size be de-rated to order?

 

LED LOADS:

Inverters are sine wave output and hence fully compatible with LED loads.

AC output inverter, de-rating for LED load high in-rush is not required, however proper sizing is required.

 

Inverters must be sized to support the total LED fixtures’ VA plus an additional 1.15 to 1.2 design margin allowance.

(VA = input volts’ x input amps; VA includes power factor & efficiency of driver)

If only fixture wattage can be found on fixture(s) spec. page (versus bulb wattage or VA

which is input volts’ x input amps), use fixture wattage times 1.25 for allowance of power factor,

efficiency and design margin.

If only lamp wattage can be found on fixture(s) spec. page (versus fixture wattage or VA

which is input volts’ x input amps), use bulb wattage times 1.35 for allowance of power factor,

efficiency and design margin.

When not sure what wattage you have, play it safe and use the 1.35 multiplier.

 

ALL OTHER LIGHTING LOAD TYPES:

Inverters must be sized to support the total fixture(s) VA (input volts’ x input amps = VA; VA includes power factor

& efficiency of ballast) plus an additional 1.15 to 1.2 design margin allowance. As 99% of the time the fixture(s) W is

very close to its VA (typ. Power factor is .99), only the 1.15 to 1.2 design margin is required. If the power factor is

known to be less than .99, this should be considered and added to the unit’s sizing calculation.

 

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