When looking for a compressor replacement, the most important piece of information required is the model number. Having a complete and accurate model number is vital because it can help you find the exact type of compressor you need for your HVAC or refrigeration system. In short, the model number of a compressor reveals some essential details, including whether the unit is an old or a new model; the replacement should have 4, 6, or 8 cylinders; or it is needed for a single or tandem configuration.
In order to understand the model numbers of York compressors for different HVAC/R applications, let’s analyze two main categories: the “J” and “Z” series.
The “J” Series
Although the most current compressor design of the “J” series is the JF version, the JG and JS versions are still widely used in numerous applications. It is for this reason we have decided to take a look at their model numbers.The model numbers of JS compressors consist of:
- The letter “J” that stands for the compressor series;
- The letter “S”, which specifies that the compressor is single stage;
- The first digit represents the number of active cylinders (4,5,6,7, or 8);
- The second digit indicates the displacement code (3- short stroke, or 4-long stroke);
- The letter after the second digit and before the dash reveals whether the compressor is an old (A, B, C, D) or new (E, F) model;
- The first letter after the dash shows the motor size (L, M, N, P, Q, S, T);
- The next two digits indicate the voltage code;
- The last letter stands for the motor vendor (G, L, or S).
Coming down to the JG compressors, it is essential to know that York has replaced the initial JG model with JK, then with JM, and recently with the PA version. The model numbers of PA compressors include:
- The letter “P”, which designates the compressor series;
- The letter “A” that represents that compressor style (starting with the “G” style, York replaced the letter “S” with the style letter);
- The first digit determines the number of active cylinders (4, 6, or 8);
- The second digit indicates the displacement code (3 – short stroke; 4 – long stroke);
- The third digit is the number of unloading steps (1, 2, or 3);
- The letter after the dash represents the size of the motor (M,N,P,Q,S,T, or V);
- The next digits or group of digits is the voltage code;
- The last letter reveals the motor vendor (G, L, or S).
One important thing to note is that early “J” compressor models don’t have a digit and/or a letter for voltage and steps of unloading. Thus, the voltage and number of unloading steps should be specified when ordering a replacement for an older “J” compressor.
The “Z” Series
Compressors Unlimited makes available two “Z” compressor versions: the “Z” and the “ZB” designs.
- The letter “Z” designates the compressor series; the “Z” version also means that the compressors in this category are style A designs, which unload on oil pressure;
- The the second position (letter “B”) of the “ZB” version indicates the compressor style B; these compressors unload with the discharge pressure;
- The first digit points out the number of active cylinders (4 or 6);
- The second letter represents the displacement code (H, J, K, M, N, R, S, W, or AE);
- The next digit reveals the number of unloading steps (0, 1, or 2);
- The first letter after the dash is the motor size code (A, D, C, or E);
- The next two digits are the voltage code;
- The last letter indicates the motor vendor (G, L, or S).
Currently, General Electric (G), Leroy Somer (L), A.O. Smith (S), and Emerson (E) are the vendors that provide the high-efficiency motors for York compressors.
To understand the importance of having the correct model number for a particular York compressor, let’s analyze the differences between two “JS” semi-hermetic compressors that look very similar at first glance.
|No. of cylinders||4||5|
|Oil charge (gal.)||3||3.5|
As there can be huge differences between two compressor models, writing down the entire model number can help you get the exact compressor you need the first time. No returns, no hassles, no delays. But regardless of whether you have the model number of the compressor that needs to be replaced, please call Compressors Unlimited at 972-286-2264, and our professionals will help you find the right compressor replacement for your system.