Johnson Controls System 450 Series Technical Bulletin

Figure 11: Active electric heat defrost control system
Table 18: Active electric heat defrost control system
Callout Description
1 A99 temperature sensor; Sn-2 defrost temperature sensor
2 A99 temperature sensor; Sn-1 space termination sensor
3 C450CCU condensing unit control module
4 C450YNN power module
5 C450SCN relay expansion module with two relay outputs
6 OUTR1, 24 VAC to 240 VAC: Controls refrigeration, either compressor or solenoid valve.
7 OUTR2, 24 VAC to 240 VAC: High-speed evaporator fan control circuit.
8
120 VAC or 240 VAC supply power terminals: Provide 120 VAC or 240 VAC supply power to optional C450YNN
power module.
9 Optional: OUTR3, 24 VAC to 240 VAC: Low-speed evaporator fan control circuit.
10 OUTR4 Defrost output
37System 450 Series C450CCU Condensing Unit Control System Technical Bulletin

Johnson Controls System 450 Series Specifications

General

Brand	Johnson Controls
Model	System 450 Series
Category	Control Unit
Language	English