Ingersoll-Rand ReliaTel, Manual, Page: 139 / 176

RT-SVD03L-EN 139
ReliaTel
™ ™
- Supply Air Tempering Control
Supply air tempering maintains the supply air
temperature above a lower limit during minimum
ventilation periods when in heat mode on a CV unit and
during inactive cool mode on a VAV unit. Supply air
tempering is available when using a BAYSENS019*/
AYSTAT666* Programmable Zone Sensor,
BAYSENS006-11/AYSTAT661-664 Mechanical Zone
Sensor, or Trane ICS system.
The unit requires an RTOM (options module) and
BAYTUBE discharge air sensing kit. Supply air
tempering will not work with a conventional
thermostat.
Enable Supply Air Tempering
Mechanical Zone Sensor BAYSENS006-
11/AYSTAT661-664
Remove the jumper from RTOM J3-1 and J3-2.
Programmable Zone Sensor
BAYSENS019*/AYSTAT666*
Change Option 4 in the options menu to 1=enabled. Or,
remove the jumper from RTOM J3-1 and J3-2.
COMM 3/4 (TCI)
Enable through appropriate menu. Supply air
tempering can also be enabled by removing the jumper
from RTOM J3-1 and J3-2.
LonTalk ® ® (LCI)
Enable through nciPersonality2. This function may not
be available with some 3rd party systems. Supply air
tempering can also be enabled by removing the jumper
from RTOM J3-1 and J3-2.
Voyager ™ ™ 27.5 to 50 tons VAV with
Staged Heat
Supply air tempering is not available. The RTOM J3-1
and J3-2 jumper is ignored.
Sequence of Operation
Constant Volume Units with Staged
Heat
When supply air tempering is enabled, the fan mode is
on, active mode is heat or emergency heat, and with
the unit not actively heating. Stage 1 of heat is turned
ON when the supply air temperature is 10°F below the
active heating setpoint.
Stage 1 of heat is turned OFF when the supply air
temperature is 10°F above the active heating setpoint
or the mode is no longer heat or emergency heat.
Should the zone temperature exceed the active heating
setpoint by 1-2F, supply air tempering will cease until
another normal heating cycle resumes.
For heat pump units, the auxiliary heat is used for
tempering.
N No otte e:: Tempering on CV units with modulating heat is
inherent to the modulating heat control design.
Variable Air Volume Units
For VAV units configured with a modulating heat type if
the unit is operating in occupied supply air cooling
mode, but the unit is not actively cooling, the unit will
energize and modulate the modulating heat output to
prevent the supply air from falling below the SA cool
setpoint deadband low end (SACSP – 3.5°F) once the
unit has de-energized all mechanical cooling (if
energized). Upon satisfying the SA tempering
requirements a five-minute ‘SA tempering delay’ timer
will start whenever the modulating heat is commanded
to 0%. This timer will be reset to 5 minutes whenever
there is an active call for heat to meet SA tempering
demands.
Tempering will be discontinued whenever the five-
minute ‘SA tempering delay’ timer has timed-out and
there is an active cooling request from the VAV
occupied mechanical cooling function.