How do I understand the air conditioner or heat pump condenser label (data plate)?
Monday, July 22, 2019
There is a lot of information on a condenser data plate that is only important for an air conditioning technician, so we will just highlight what might be relevant for a homeowner.
1 - Serial Number. Although the number is only for a particular condenser, the year of manufacture is usually encoded in the front of it, and often the first two or second two numbers are the year of manufacture. For this Carrier heat pump, it is the second two numbers, but varies according to manufacturer, and some of them change their coding over time. Also, there are more complicated systems using letters for the year and a few companies don’t encode the year of manufacture in the serial number at all. To learn the serial number format for your brand, enter the brand name in the search bar at the top of this page.
2 - Model Number. Somewhere in the middle of the model number is a two-digit number that is divisible by 6, and it will tell you the cooling capacity of the unit in tons after conversion from BTU. You need to know that 12,000 BTU equals one ton of air conditioning, which is the measure normally used in the United States. The thousands are dropped off of the number, so 24 equals 2 tons, as at this data plate, and 30 is 2.5 tons, and 60 means 5 tons. You can also use the model or product number to look up more information on the system on the internet.
3 - Factory Charged. This will tell you whether the system uses the older R-22 refrigerant, which is being phased out, or the current R-410A.
4 - RLA. The Running Load Amperage is the amount of current in amps that the compressor motor will draw after startup, when operating.
5 - LRA. The Locked Rotor Amperage is the necessary surge of electricity required to overcome inertia and start up the compressor. This number will be important to you if you plan to run your a/c system using a generator during a power outage. The generator must be able to handle this brief surge of amps, usually 4 or 5 times the RLA.
6 - Max Circuit Breaker or Fuse. This is always approximately twice the RLA of the compressor. The only time this number becomes a problem is when the system has been changed out for a newer, more energy one, and the breaker for the circuit is not also changed out to a lower amperage rating.
7 - Date of Manufacture. - Sometimes the date of manufacture is directly stated and it is not necessary to decode the serial number. Trane, for example, often places the date of manufacture at the upper right of the data plate.
8 - Heat Pump or Cooling Air Conditioner. Somewhere near the bottom of the data plate, and often in small letters, it will state whether whether the condenser is a heat pump (contains a device to reverse the flow of refrigerant from cooling to heating) or a cooling air conditioner (only functions in cooling mode, and usually part of a system with gas furnace).
9 - Name of Manufacturer. This is often also small letters and may be an acronym. For example, CAC/BDP is a division of the Carrier Corporation.
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To learn more about heating and air conditioning systems, see these other blog posts:
How To Look At A House
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