Lennox CHA16 Service Manual page 38

Contactor K18
4th Stage
(60kW 208/230V only)
Primary Limit S15
(208/230V only)
Redundant Limit S63
(460 & 575V only)
Primary Limit S15
(460 & 575V only)
Patch Plate
(in lieu of limit
208/230V only)
Secondary Limit S20
(2 each element)
208/230V,15kW-2
208/230V,30kW-4
208/230V,45kW-6
208/230V,60kW-8
460V & 575V,15kW-2
460V & 575V,30kW-4
460 & 575V,45kW-6
460V & 575V,60kW-8
460V & 575V,75kW-8
4th Stage
3rd Stage
Time Delay DL5
Time Delay DL4
(208/230V
(all 208/230V
60kW units only)
45kW & 60kW units)
Contactor K17
3rd Stage
(45kW and 60kW
208/230V units only)
K18
2nd Stage
Time Delay DL2
1st Stage Heat Demand
(all units equipped
Pilot Relay K9
with multiple stage
heaters)
Page 38
Contactor K16
2nd Stage
(208/230v 30kW and
all 45kW and 60kW units)
K17 K16
F3
F3 F3
T2
GND
DL5
L3
DL4
DL2 K9 K19
Electric Heat
Transformer T2
2nd Stage Heat Demand
Pilot Relay K19
Contactor K15
1st Stage (all units)
K15
1st Stage Fuse F3
(all units)
F3
4th Stage Fuse F3
(208/230V 60kW only)
2nd Stage Fuse F3
(460 & 575V units
if equipped with
multiple stages)
2nd Stage Fuse F3
(208/230V units if
equipped with
multiple stages)
3rd Stage Fuse F3
(208/230V units
if equipped with
L2 L1
multiple stages)
Electric Heat
Terminal Strip TB3