Stage Thresholds; Stage Inhibits - Trane TCONT850 Installation Manual

Installation Guide
6.6

Stage Thresholds

The threshold to allow operation is a Load Value greater
than 5 and operation is always terminated with a Load
Value less than 1.
Load Value also determines when additional stages of
operation are requested. To prevent rapid cycling between
stages, a stage threshold is enforced. The stage threshold
is dependent on the applied system.
COMPRESSOR STAGING THRESHOLDS
STAGE 2
100-110 100-110 Y1 to Y2 Y1 to Y2
100-115 100-115 HP to W1 HP to W1
100-125 100-125
AUX ELECTRIC HEAT - STAGING THRESHOLDS
STAGE 2
100- 100-
Compressor to W1 Compressor to W1
115 115
200- 200-
215 215
AUX FOSSIL HEAT - STAGING THRESHOLDS
STAGE 2
100- 100- Inhibit - Compressor to W1 Inhibit - Compressor to W1
125 125
175- 175-
190 190
AUX WET HEAT - STAGING THRESHOLDS
STAGE 2
100- 100- Compressor to W1 Compressor to W1
125 125
Note: Stage Thresholds do not apply to Variable Speed
Outdoor Unit operation.
14
HP to Dual Fuel HP to Dual Fuel
STAGE 3 STAGE 4
W1 to W2 W1 to W2
300- 300-
W2 to W3 W2 to W3
315 315
STAGE 3
W1 to W2 W1 to W2
175- 175-
W2 to W3 W2 to W3
190 190
STAGE 3
200- 200-
W1 to W2 W1 to W2
215 215
6.7

Stage Inhibits

When the stage threshold is exceeded, a stage inhibit is
applied. The stage inhibit calculates the rate of recovery
over a 10-minute period and determines if the next stage is
required to meet the current demand. If the rate of recovery
is great enough, a new 10-minute inhibit is enabled. The
Control will not go to the next stage of operation until it
determines that the current stage cannot satisfy the current
demand. Stage inhibits only apply between compressor
stages and compressor heat to indoor heat. Stage inhibits
do not apply to indoor heat stages.
Stage inhibits can be disabled in the 850 Control
Installer Setup>Comfort Settings.
Stage Inhibits - Compressor Staging
Y1 "ON"
LV = 110
START INHIBIT
10 Minutes
LOAD VALUE (LV)
Stage Inhibits - Compressor to Aux Heat
Y1 "ON"
LV = 115
START INHIBIT
10 Minutes
LOAD VALUE (LV)
Stage Inhibits - Duel Fuel
Y1 "ON"
LV = 125
START INHIBIT
10 Minutes
LOAD VALUE (LV)
Note: Stage Inhibits do not apply to Variable Speed
Outdoor Unit operation.
Y2 "ON" Y1 "ON"
LV = 100
W1 "ON" W1 "OFF"
LV = 100
Y1 "ON"
45 Second
Cool Down
W1 "ON"
LV = 100
18-HD73D1-9E-EN