tekmar 262 Boiler Control Installation User Manual

Page 9

9 of 36

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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 tempera-

ture to the system is raised above its normal values for a period of time
to provide a faster recovery from the setback temperature of the building.
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 or 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.

Section B2 —Alternate Boiler Demands (Mode = —1—)

In addition to using conventional thermostats to provide a boiler demand as described in Section B1, the 262 can use a number of other
methods to provide a

Boiler Demand.

10K INDOOR SENSOR (10K = INDR)

Set the 10K item to INDR to add an indoor sensor for temperature control of a single zone boiler
system. The indoor sensor is connected to the

Com and 10K terminals (16 and 17). In addition,

power must be applied to the

Boiler Demand terminals (1 and 2) as described in Section B1.

With the indoor sensor connected, the 262 is able to sense the actual room temperature. With
this information, the 262 provides a more constant water flow through the system. At the same
time, indoor feedback fine tunes the supply water temperature in the system to prevent over
heating or under heating. To adjust the room temperature for the zone, use the ROOM
Occupied or UnOccupied setting in the Adjust menu at the control.

10K BOILER ZONE CONTROL (10K = ZoIn)

Set the 10K item to ZoIn to add indoor temperature feedback control of multiple zones. Control
of the zones is provided by connecting a tekmar Zone Control to the

Com and 10K terminals

(16 and 17) of the 262. The zone control provides its own internal

Boiler Demand to the 262.

In this case, there is no need to provide an external

Boiler Demand as described earlier in

Section B1. The zone control is capable of automatically adjusting the Boil TRG temperature
to improve building occupant comfort and system performance.

10K SLAB SENSOR (10K = SLAB)

Set the 10K item to SLAB to add a slab sensor for temperature control of a single zone system.
The 262 can use a slab sensor to control the actual slab temperature. A slab sensor is placed
in the slab and connected to the

Com and the 10K terminals (16 and 17). Power must be

applied to the

Boiler Demand terminals (1 and 2) as described in Section B1. With the slab

sensor connected, the 262 will limit the supply temperature in order to maintain the slab sensor
between the SLAB MIN and SLAB MAX settings. This application is available only when
Boil MIN is set to OFF.

Slab Min (SLAB MIN)

The SLAB MIN sets the minimum allowed core temperature of the slab as long as the control is not in a WWSD. Caution should be
used when adjusting the SLAB MIN setting as this may lead to overheating of the zone during mild conditions. If the AWAY setting
is selected in the

Schedule menu, the 262 ignores the SLAB MIN setting.

Slab Max (SLAB MAX)

The SLAB MAX sets the maximum allowed core temperature of the slab. If the slab is to be maintained at a fixed core temperature,
set SLAB MAX and SLAB MIN items to the same setting.

ROOM TEMPERATURE UNIT (RTU) (10K = NONE)

If the system consists of a single zone, temperature control of that zone can be provided by using an RTU. The RTU is connected to
the

Com and tekmar Net

tN1 / tN2 terminals (15 and 16). In addition, power must be applied to the Boiler Demand terminals (1 and

LR 58233

E150539

tekmar

Zone Control

Zone Control 367
One & Two Stage / One Stage & Floating

Power

Heat Required

Zone 2 / Hi stage /
Close / Ventilation

System Pump

24 hr. Timer

• Dial the desired duration
of the UnOccupied period.
• Press start button at the time of day
you want the UnOcc. period to begin.
Timer Active light turns on.

Start

UnOccupied

Duration

0 = always Occupied
24 = always UnOccupied

Zone 1 / Lo stage /
Open / Cooling

Zone 4 / Hi stage
Close

Zone 3 / Lo stage
Open

Zone 6 / Hi stage
Close

Zone 5 / Lo stage
Open

°F

(21

°C)

40
(4)

100
(38)

UnOccupied

Occupied

Optimum Start / Stop

UnOccupied

Timer Active

12 hrs.

tekmar

262 Control

Item

Boiler Control 262
Two Stage Boiler & DHW / Two Stage DHW

LR 58223

N R T L / C

Boiler Demand

DHW Demand

Setpoint Demand

WWSD

Minimum

Maximum

°F

Vie

Occ

tekmar

262 Control

tekmar

Slab Sensor

Item

Boiler Control 262
Two Stage Boiler & DHW / Two Stage DHW

LR 58223

N R T L / C

Boiler Demand

DHW Demand

Setpoint Demand

WWSD

Minimum

Maximum

°F

Vie

Occ

UnOcc to Occ

Boost

Boil TRG (Occupied)

ater T

emperature

Time

Boost setting - 20 minutes to 8 hours

Boil TRG (UnOccupied)

Self Adjusting

Water Temperature

tekmar

Indoor Sensor

tekmar

262 Control

Item

Boiler Control 262
Two Stage Boiler & DHW / Two Stage DHW

LR 58223

N R T L / C

Boiler Demand

DHW Demand

Setpoint Demand

WWSD

Minimum

Maximum

°F

Vie

Occ