AC compressor spec

Normally on the AC condenser unit, you will see some numbers for LRA and RLA, you should have these for both compressor and fan motor. Here are what they mean:

LRA - Lock Rotor Amps.  

The current you can expect under starting conditions when you apply full voltage. It occurs instantly during start up. This is normally a lot higher than RLA. For example, 104 vs 19.2

RLA - Rated Load Amps

The maximum current a compressor should draw under any operating conditions. Often mistakenly called running or run load amps which leads people to believe, incorrectly, that the compressor should always pull these amps.

FLA - Full Load Amps

Changed in 1976 to "RLA - Rated Load Amps". 

Comments

Post a Comment

Popular posts from this blog

Heat Pump Refrigerant Flow Chart

Image
Heat pump system basically works in both winter and summer time because it converts condenser and evaporator role. In winter time, the indoor unit becomes condenser and outdoor unit becomes evaporator, in summer time, the indoor unit becomes evaporator and outdoor unit becomes condenser. The liquid line out of the compressor always contains liquid, the vapor line into the compressor always contains vapor. When liquid hit reversing valve, things change in winter and summer mode. See the chart below: The refrigerant lines that connect the indoor coil with the outdoor coil are the gas line (hot gas in winter and cold gas in summer) and liquid line. The liquid line is always the liquid line; the flow reverses from season to season.
Read more

CFM and AC

Image
AC and heating size chart:       Typically we need about 1 CFM of air flow per square foot of floor area of conditioned space provided that the ceiling height is about 8 feet above the floor, with a typical number of windows and doors and typical building insulation and heat gain or loss. That is 1 sqft x 8ft = 8 cubic feet space needs 1 CFM. You can use this to roughly calculate how much CFM needs for your space. (Tong added) Examples of components for which air velocity (speed through the device) is particularly important are given in the HVAC Air Velocity table below. Typical HVAC System Air Velocity Specifications (速度， 不是CFM） HVAC Component Recommended Air Velocity / Flow Comments Air Ducts - main trunk, typical 700 - 900 fpm Residential Air Ducts - branch, typical 600 - 700 fpm Residential Air Ducts - target 400 fpm Residential Ducts run through conditioned space ...
Read more

In. W.C in HVAC

When measuring static pressure, the unit of measurement used is inches of water column, which is often shown as an abbreviation such as “in. wc ,” “in. wg” or “in. H2O.” One key to interpreting and diagnosing static pressure is to first understand how pressures change throughout an HVAC system. Static pressure is the amount of pressure a fan has to push and pull against to move air through a duct system. Static pressure is exerted equally on all sides of a duct system. This pressure is similar to that found by blowing up a balloon. When measuring static pressure, the unit of measurement used is inches of water column, which is often shown as an abbreviation such as “in. wc,” “in. wg” or “in. H 2 O.” Supply Plenum A plenum is an air-distribution box attached directly to the supply outlet of the HVAC equipment that heats or cools the air to make the house comfortable. The ductwork that distributes the heated or cooled air to individual rooms of the house connects to the plenum....
Read more