SECTION 20: S
EQUENCE
OF
O
PERATION
101 of 198
20.5.6 Space Pressure Controller With Minimum
Air
This option
u
ses a
bu
ilding press
u
re sensor (for DDC
controls) or differential press
u
re s
w
itch [photohelic
optional] (for con
v
entional relay logic controls) to
monitor differential press
u
re
b
et
w
een the o
u
tside of
the space (typically o
u
tside the str
u
ct
u
re) and the
heated space. The air handler
w
ill ens
u
re proper air
deli
v
ery
b
y
u
sing a discharge damper, inlet/
recirc
u
lating dampers or VFD to modify the airflo
w
w
hen a press
u
re change is req
u
ired. The press
u
re
drop across the
bu
rner is maintained
b
y the
motorized profile dampers
w
hich are set
u
p
electrically as a Master/Sla
v
e. Most installations
req
u
ire a set point of 0.01 in
w
c to 0.02 in
w
c to
achie
v
e adeq
u
ate press
u
re control in the
bu
ilding.
20.5.7 Electronic Space Pressure Control
This is a solid state controller that monitors the space
ser
v
iced
b
y the air handler and a reference point
(
u
s
u
ally o
u
tside the str
u
ct
u
re) for press
u
re
differential. It maintains the selected press
u
re set
point
b
y
v
arying the o
u
tp
u
t of airflo
w
from the handler
u
sing
v
ario
u
s options.
20.6 Ni
g
ht Setback Options
20.6.1 Ni
g
ht Setback with Occupied/Unoccupied
Switch
This option pro
v
ides man
u
al control of occ
u
pied and
u
nocc
u
pied cycles, operated
b
y an occ
u
pied/
u
nocc
u
pied s
w
itch. It incl
u
des a line
v
oltage room
thermostat (shipped loose) and an occ
u
pied/
u
nocc
u
pied s
w
itch (mo
u
nted on remote panel).
D
u
ring the
u
nocc
u
pied cycle, the air handler remains
off
u
ntil the room thermostat calls for heat. At that
time, the air handler goes to a standard daytime
seq
u
ence
u
ntil the thermostat is satisfied.
20.6.2 Ni
g
ht Setback with Electro-Mechanical
Time Clock
This option pro
v
ides a
u
tomatic control of occ
u
pied
and
u
nocc
u
pied cycles, operated
b
y an
electromechanical time clock. It incl
u
des a se
v
en-day
electro-mechanical time clock (shipped loose). The
time clock can
b
e set for different on and off times
any of the days d
u
ring the se
v
en-day period. D
u
ring
the
u
nocc
u
pied cycle, the air handler remains off
u
ntil
the room thermostat calls for heat. At that time, the
air handler goes to a standard daytime seq
u
ence
u
ntil the thermostat is satisfied.
20.6.3 Ni
g
ht Setback with Electronic Time Clock
This option pro
v
ides a
u
tomatic control of occ
u
pied
and
u
nocc
u
pied cycles, operated
b
y an electric time
clock. It incl
u
des a se
v
en-day electronic time clock
(mo
u
nted on the remote panel). The time clock can
b
e set for different on and off times any of the days
d
u
ring the se
v
en-day period. D
u
ring the
u
nocc
u
pied
cycle, the air handler remains off
u
ntil the room
thermostat calls for heat. At that time, the air handler
goes to a standard daytime seq
u
ence
u
ntil the
thermostat is satisfied.
Summary of Contents for TT Series
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Page 136: ...TT SERIES INSTALLATION OPERATION AND SERVICE MANUAL 130 of 198 FIGURE 114 Regulator RV61 ...
Page 167: ...SECTION27 TROUBLESHOOTING 161 of 198 ...
Page 175: ...SECTION27 TROUBLESHOOTING 169 of 198 ...
Page 177: ...SECTION27 TROUBLESHOOTING 171 of 198 ...
Page 198: ...TT SERIES INSTALLATION OPERATION AND SERVICE MANUAL 192 of 198 ...
Page 202: ...TT SERIES INSTALLATION OPERATION AND SERVICE MANUAL 196 of 198 ...
Page 203: ...SECTION 28 THE WEATHER RITE TT SERIES WARRANTY 197 of 198 ...
Page 204: ...TT SERIES INSTALLATION OPERATION AND SERVICE MANUAL 198 of 198 ...