tekmar 362 Mixing Control Installation User Manual

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16 17

Com

UnO

Timer Switch

UnOcc

Schd

Ovr

UnOcc to Occ

Boost

Mix TRG (Occupied)

ater T

emperature

Time

Boost setting - 20 minutes to 8 hours

Mix TRG (UnOccupied)

Self Adjusting

Water Temperature

SETBACK (UnOccupied)

To provide greater energy savings, the 362 has a setback capability. With setback, the supply
water temperature in the system is reduced when the building is not used (AWAY) or when
the building is UnOccupied. By reducing the supply water temperature, air temperature in the
space may 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 362 into an UnOccupied mode. Any time the

UnO Sw (16)

and the

Com (17) 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

362 adjusts the supply water temperature(s) based on the

UnOcc settings made in

the control.

Internal Overrides

The 362 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 is displayed in the LCD.

Temporary (TMPY)

If a temporary override is selected, the 362 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 362 operates in the selected override mode until a new override is selected.

Away (AWAY)

If the AWAY override is selected, the 362 operates with a fixed WWSD of 62˚F (17˚C) and a fixed room temperature of 62˚F (17˚C).

BOOSTING (BOOST)

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.

SOFT START (SOF STRT)

The SOF STRT function allows the 362 to slowly ramp the water temperature up to the required supply temperature. By allowing the
temperature in the system to be adjusted slowly, the control reduces any thermal expansion noises and stresses that may be caused
by a quick change in supply water temperature.

Sequence, Section B