Update: Correct equation for ChillerEIRfPLR is available in the Engineering Reference document up to V8.4.

Where do you see in the documentation that the definition of f3 is EIRact/EIRcap ? Or is it simply your translation of the variable name?

Two thoughts:

1) Your explanation seems to confirm that ChillerEIRFPLR is indeed equal to what I refer to as bar(f)3.

2) My definition of f3, i.e. NOT bar(f)3, is based on: "The output of this curve is multiplied by the reference EIR (inverse of the reference COP) and the Energy Input to Cooling Output Ratio Function of Temperature Curve to give the EIR at the speicfic temperature and part-load ratio at ehich the chiller is operating." (http://bigladdersoftware.com/epx/docs...).

so, further to item 2): EIRref = Pref/Qref, EIRact = Pact/Qact, ChillerEIRFTemp = EIRcap/EIRref, where I am assuming that ChillerEIRFTemp is the "Energy Input to Cooling Output Ratio Function of Temperature Curve" of the above definition. Therefore, ChillerEIRFPLR * EIRref * ChillerEIRFTemp = EIRact, or ChillerEIRFPLR * EIRref * EIRcap/EIRref = EIRact. Hence: ChillerEIRFPLR = EIRact/EIRcap, which is my definition of f3.

so, I am thinking if your derivation from the EnergyPlus Engineering reference is indeed on target, then perhaps all that needs to e changed is the verbal definition in http://bigladdersoftware.com/epx/docs....