Application Note 1024: Supplemental Heat Control ©2012 Mitsubishi Electric US, Inc.
The P-Series, SEZ and SLZ indoor units, when installed with MXZ, PUZ or SUZ heat pump outdoor units, can interface and enable supplemental and auxiliary heat sources using an indoor board connector (CN-24 or CN-152, depending on indoor unit). For indoor units connected to PUY outdoor units, external heat control does not function. (Please note that at this time M-Series indoor units (MS/MSZ/MFZ) do NOT support any supplemental heat control or interface capabilities.
Supplemental Heat Control via CN-24 for PLA, PCA and SLZ Indoor Units CN-24 controls are indicated in Figure 1and require no setup at the remote controller. This function is only available in heating operation. Figure 1. CN-24 controls Figure 2 illustrates a typical wiring diagram for PLA, PCA and SLZ indoor units using CN-24: Figure 2.
Figure 3. CN4YControls Selecting setting #2 for Setup Function 123 on MHK1 (or Mode 23 on PAR-21MAAU) allows Setup Function 125 on MHK1 (or Mode 25 on PAR21MAA) and CN4Y to be used to control the indoor unit fan during defrost and error conditions as shown in Figure 3. Table 2 and 3 lists the settings to be used to achieve the fan operation desired. Table 2.
Figure 4 illustrates a typical wiring diagram for PEA(D) and SEZ indoor units using CN24: Figure 4. Wiring Diagram for PEA(D) and SEZ indoor units Supplemental Heat Control via CN-152 for PKA Wall-mounted Indoor Units CN-152 controls are indicated in Figure 5 and require no setup at remote controller. This function is only available in heating operation. Figure 5. CN-152 Controls Figure 6 illustrates a typical wiring diagram for PKA wall-mounted indoor unit using CN152. CN-152 Yellow Brown Figure 6.
Wiring restrictions for ALL field wiring in all of the above diagrams: Keep the length of the cable connecting to the circuit board of the indoor unit shorter than 32 ft. (10 meters). Wire size should be 22 ~ 16 AWG (0.5 mm2 ~ 1.25 mm2) depending on length and conditions. All wiring should conform to all local codes and the National Electric Code where applicable. August 2012 Application Note 1024 ©2012 Mitsubishi Electric US, Inc.
