Lennox CHA16 User Manual

Page 35
10-Time Delay DL5
Time delay DL5 is only used in 50 and 75kW
208/230V electric heat units. The delay is identical
to DL2 and DL4. DL5 allows four stages of heat by
providing a timed interval between the third and
fourth heating elements.
11-Time Delay DL18
Time delay DL18 is only used in 75kW 208/230V
electric heat units. The delay is identical to DL2,
DL4 and DL5. DL18 allows five stages of heat by
providing a timed interval between the fourth and
fifth heating elements. DL18 is energized only after
time delay DL5 closes.
12-High Temperature Limit S15 (Primary)
S15 is the primary high temperature limit. It is located
in the electric heat unit immediately downstream
from the heating elements. S15 is a singlepole
singlethrow normally closed thermostat wired in se
ries with the first stage contactor coil. The thermostat
actuates at temperatures shown in table 12. The tem
perature differential is factory set and is not adjust
able.
S15 SPST AUTO-RESET HIGH TEMPERATURE LIMIT
Open on Rise Close On Fall
All
Unit
175°F + 5°F 135°F + 10°F
TABLE 12
7.5 Tons And Under
Voltage
145°F + 5°F 105°F + 6°F
10 Thru 12.5 Tons
208/230V
125°F + 5°F95°F + 6°F
15 Tons And Larger
460 & 575V
All
145°F + 5°F* 105°F + 6°F *
130°F +
5°F90°F + 6°F
*Early Production
When S15 opens, indicating a problem in the system,
contactor K15 is deenergized. When K15 is deener
gized, first stage and all subsequent stages of heat are
deenergized. Since the indoor blower is controlled by
demand (K9 remains energized), the indoor blower con
tinues operating.
13-High Temperature Limit S63 (Redundant)
S63 is a redundant (primary) temperature limit fac
tory installed in 460 & 575V units. The redundant
limit is operable only when connected to CHP16
units and does not function when connected to
CHA16 units.
14-High Temperature Limit S20 (Secondary)
Each heating element assembly is electrically connected
to two high temperature limits S20 (refer to wiring dia
grams in back of this manual). Each limit is connected in
series with one leg of the threephase element assembly.
The third leg of each assembly is not equipped with a lim
it. Threephase operating characteristics allow one of the
other two limits to protect the third leg.
Each S20 limit is physically located adjacent to the
element it is protecting. S20 is a singlepole single
throw normally closed thermostat. The thermostat ac
tuates at 185°F + 8°F on a temperature rise and can
not be reset. Once tripped, it must be replaced.
15-Fuse F3
F3 is a current limiting fuse connected in series with
each leg of electric heat (each stage of electric heat
uses three fuses). Fuses used in CHA16 series heat
ing sections are shown in table 13.
kW &
Voltage
TABLE 13
Fuse F3
1st Stage
Fuse F3
2nd Stage
Fuse F3
3rd Stage
Fuse F3
4th Stage
(3 Fuses) (3 Fuses) (3 Fuses) (3 Fuses)
---
---
--- ---
---
---
60 Amp
250V
--- ---
30 Amp
600V
--- ---
60 Amp
250V
60 Amp
250V
---
60 Amp
600V
------ ---
60 Amp
250V
60 Amp
250V
60 Amp
250V
---
60 Amp
600V
30 Amp
600V
60 Amp
250V
60 Amp
250V
60 Amp
250V
60 Amp
250V
60 Amp
600V
60 Amp
600V
---
208/230V
460 & 575V
208/230V
460 & 575V
208/230V
460 & 575V
208/230V
460 & 575V
CHA16 ELECTRIC HEAT SECTION FUSE RATINGS
------ ---
---
60 Amp
250V
--- ---
208/230V
---
60 Amp
250V
60 Amp
250V
---
60 Amp
600V
------ ---
208/230V
460 & 575V
60 Amp
600V
60 Amp
600V
30 Amp
600V
---
460 & 575V
10kW
10kW
15kW
15kW
20kW
20kW
30kW
30kW
45kW
45kW
60kW
60kW
75kW
60 Amp
600V
60 Amp
600V
60 Amp
600V
---
460 & 575V
90kW
--- ---
60 Amp
250V
60 Amp
250V
60 Amp
250V
---
60 Amp
600V
30 Amp
600V
208/230V
460 & 575V
40kW
40kW
60 Amp
600V
30 Amp
600V460 & 575V
50kW
--- ---
60 Amp
600V
30 Amp
600V460 & 575V
50kW
60 Amp
600V
30 Amp
600V
460 & 575V
30 Amp
600V
208/230V
75kW
60 Amp
250V
60 Amp
250V
Fuse F3
5th Stage
(3 Fuses)
---
---
---
---
---
---
---
---
---
---
---
---
---
---
---
---
60 Amp
250V
60 Amp
250V
60 Amp
250V
---
---

Lennox CHA16 Specifications

General

Brand	Lennox
Model	CHA16
Category	Air Conditioner
Language	English