tekmar 363 Universal Reset Control Installation - Manual (Page 5)

5 of 40 Copyright © D 363 -
12/08
Fin–tube Convector (CONV)
A convector terminal unit is made up of a heating element with fins on it. This type of terminal
unit relies on the natural convection of air across the heating element to deliver heated air
into the space. The amount of natural convection is dependant on the supply water
temperature to the heating element and the room air temperature.
Radiator (RAD)
A radiator terminal unit has a large heated surface that is exposed to the room. A radiator
provides heat to the room through radiant heat transfer and natural convection.
Baseboard (BASE)
A baseboard terminal unit is similar to a radiator, but has a low profile and is installed at the
base of the wall. The proportion of heat transferred by radiation from a baseboard is greater
than that from a fin-tube convector.
SETBACK (UnOccupied)
To provide greater energy savings, the 363 has a setback capability. With setback, the supply water temperatures in the system are
reduced when the building is not used (AWAY) or when the building is UnOccupied. By reducing water temperatures, air temperature
in the space can be reduced even when thermostat(s) are not turned down. This feature is
enabled by setting the
Setback / None DIP switch to the Setback position, and providing either
an external signal or an internal override. Note: AWAY does not require the DIP switch =
Setback.
External UnOccupied
An external signal can place the 363 into an UnOccupied mode. Any time the UnO Sw (22)
and the Com (23) terminals are shorted together, the control operates in the UnOccupied
mode. When in the UnOccupied mode, the UnOcc segment is displayed in the LCD. The
363 adjusts the supply water temperature(s) based on the UnOcc settings made in the
control.
Internal Overrides
The 363 has a number of setback overrides that are selected through the Schd Menu. These
setback overrides have priority over any external setback signal. Any time an override is in
effect, the
Ovr segment displays in the LCD.
Temporary (TMPY)
If a temporary override is selected, the 363 operates in the selected override mode for 3
hours. Once completed, the control reverts to the previous operation.
Permanent (PERM)
If a permanent override is selected, the 363 operates in the selected override mode until a new override is selected.
Away (AWAY)
If the AWAY override is selected, the 363 operates with a fixed WWSD of 62˚F (17˚C) and a fixed room temperature of 62˚F (17˚C).
Any DHW demand is ignored. The setpoint operation is not affected by the AWAY
override.
BOOSTING (Boil BST / MIX BST)
When the control changes from the UnOccupied to the Occupied mode, it
enters into a Boosting mode. In this mode, the supply water temperatures to
the system are raised above their normal values for a period of time to
provide a faster recovery from the building’s setback temperature. The
maximum length of the boost is selected in the user interface. This
setting is only available if a
Characterized Heating Curve is selected; It is
not available for a Reset Ratio, and not needed or available if a tekmar Zone
Control is used.
Typical settings for the BOOST function vary between 30 minutes and two
hours for a building that has a fast responding heating system. For a
building that has a slow responding heating system, a setting between four
hours and eight hours is typical. After a BOOST time is selected, the setback timer must be adjusted to come out of setback some time
in advance of the desired
Occupied time. This time in advance is normally the same as the BOOST setting. If the building is not up to
temperature at the correct time, the BOOST setting should be lengthened and the setback timer should be adjusted accordingly. If the
building is up to temperature before the required time, the BOOST setting should be shortened and the setback timer should be adjusted
accordingly. If the system is operating near its design conditions or if the supply water temperatures are being limited by settings made
in the control, the time required to bring the building up to temperature may be longer than expected.
22 23
Com UnO
Sw
Timer Switch
UnOcc
Schd
Ovr
CONV
RAD
BASE
UnOcc to Occ
Boost
Boil TRG (Occupied)
W
ater T
emperature
Time
Boost setting - 20 minutes to 8 hours
Boil TRG (UnOccupied)
Self Adjusting
Water Temperature