Robertshaw 9520 - Manual (Page 5)

11. Terminal screws are loosened. Insert wires into terminal strip
(Figure 4) matching the label to the corresponding terminal
(see Wiring Diagrams below). Tighten screws.
5
Typical heat pump with cool active reversing valve and auxiliary/emergency heat.
O B
9520 WIRING SAMPLE #1
Y1 E G W2 C L R Y2
Typical heat pump with heat active reversing valve and auxiliary/emergency heat.
9520 WIRING SAMPLE #2
C L R Y2 Y1 E G W2 O B
Typical heat pump with heat active reversing valve and auxiliary/emergency heat.
Does not have separate wire for emergency heat (jump W2 & E).
9520 WIRING SAMPLE #3
B Y1 E G W2 C L O R Y2
Jumper
Typical heat pump with cool active reversing valve, auxiliary/emergency heat
and second stage of cooling. System fault indicator connected (L terminal).
E G O B
9520 WIRING SAMPLE #4
C W2 L R Y2 Y1
FIGURE 4