tekmar 262 Installation
- Data Brochure
D 262
Boiler Control 262
12/08
The Boiler Control 262 is a micro processor based control designed to maximize the comfort and efficiency of a hydronic heating system.
The control is designed to operate in two distinct modes.
MODE —1— (Two Stage Boiler & DHW) allows for the control of two separate on /off boiler stages (or one low / high fire) based on outdoor
air temperature, control for indirect Domestic Hot Water (DHW) generation and a Setpoint load. For single zone temperature control
with indoor temperature feedback, a Room Temperature Unit (RTU) or indoor sensor may be connected to the 262. Multiple zone
temperature control is achieved by using either a conventional thermostat system or by connecting a tekmar Zone Control to the 262.
MODE —2— is designed specifically for dedicated DHW applications. In Mode 2, the 262 can stage and rotate two on / off boiler stages
(or one low / high fire) in order to provide heat to a DHW storage system.
The 262 control includes a large Liquid Crystal Display (LCD) in order to view system status and operating information. The same LCD
is used when setting up and installing the control. Standard features include Equal Run Time Rotation, intelligent boiler operation, digital
temperature readouts, and pump exercising. With the addition of a monitoring feature, it is now possible to track pump and boiler running
hours, DHW tank temperature, outdoor and system high and low temperatures, boiler firing cycles, plus many other useful items.
Several energy saving features have been incorporated into the 262 such as Warm Weather Shut Down (WWSD), DHW post purge,
system setback, DHW priority and an automatic differential for boiler operation.
Reset Ratio
Characterized
Heating Curve
1 Two Stage Boiler & DHW
2 Two Stages for DHW
Do not apply power
16
18 19
15
tN1/
UnO
Com
10K Out
tN2
Sw
20
DHW17Com
Test
21 22
Boil
off
not testing
red
testing
red
For maximum heat,
Tes t
press and hold
button for 3 seconds.
Meets Class B:
Canadian ICES
FCC Part 15
Date Code
H1109F
Input
Outdoor
Sensor
Input
Universal
Sensor
Input
Universal
Sensor
Included
Optional
Input
tekmar
Timer
Included
Note:
Boiler, DHW, or setpoint
demand must be powered
with 20 to 260 V (ac)
before the boiler is able
to fire.
Input
Boiler
Demand
signal
Input
DHW Demand
signal
Input
Setpoint
Demand
signal
Input
120 V (ac)
Power
Supply
View
F
°
1
2
1
Item
Menu
Boiler Control 262
Two Stage Boiler & DHW / Two Stage DHW
7
6
8
10
Boiler
231
4
5
Com
DHW
Setp
Dem
Dem
Dem
Power
NL
Boil
P1
9
DHW
Pmp / Vlv
Boiler Demand
DHW Demand
Setpoint Demand
WWSD
Minimum
Maximum
12
11
14
13
Stage
Stage
11 2 2
Setback
None
Operating Modes
See product literature
INSTALLATION CATEGORY II
Made in Canada by
tekmar Control Systems Ltd.
tektra 929-03
Power 115 V ±10% 60 Hz 900 VA
Relays 230 V (ac) 7.5 A 1/3 hp, pilot duty 240 VA
Demands 20 to 260 V (ac) 2 VA
Signal wiring must be rated at least 300 V.
Wiring must be rated 194°F (90°C) minimum
Output
Boiler System
Pump
M
Output
DHW Pump OR
DHW Valve
Output
Boiler
Output
Boiler
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Vie
°
F
WWS
1%%2
!
ItemMenu
Input
Room
Temperature
Unit (RTU)
Vie
1%%2
ItemMenu
OR
Input
Remote
Display
Module (RDM)
Input
Slab Sensor
OR
OR
Input
70
Indoor Sensor
°
F
WWS
!
LR 58233
E150539
Input
Zone Control
Copyright © D 262 -12/08
How To Use The Data Brochure
This brochure is organized into four main sections. They are: 1) Sequence
Troubleshooting
4)
Sequence of Operation
apply to your installation.
The
Control Settings
referenced to the specific section in the
. The
Sequence of Operation
, as this contains important information on the overall operation of the control. Then refer to the sub sections that
section of this brochure illustrates the menu screens that are built into the control. These menu settings are
Sequence of Operation
section has four sub sections. We recommend reading
.
Table of Contents
of Operation
, 2)
Installation
, 3)
Control Settings
Section A: General
, and
of the
User Interface .......................................... pg 2
Description of Display Elements ............ pg 3
Sequence of Operation ............................ pg 4
Section A: General
Section B: Boiler Reset
Section C: DHW
Section D: Setpoint ..
Installation ............................................... pg 14
Electrical Connections.................. pg 14
Testing The Wiring........................ pg 16
DIP Switch Settings ................................ pg 18
Reference Material: Essay E 003: Characterized Heating Curve and Reset Ratio
........................ pg 4
................. pg 6
........................... pg 10
..................... pg 13
Access Levels ................................................ pg 19
Control Settings ............................................. pg 20
View Menu
Adjust Menu
Schedule Menu
Miscellaneous Menu
RTU Menu
Testing and Troubleshooting ...................... pg 27
Monitor Menu
Error Messages
Technical Data ............................................... pg 36
Limited Warranty ........................................... pg 36
........................................... pg 20
........................................ pg 21
................................... pg 24
.......................... pg 25
........................................... pg 25
...................................... pg 29
.................................. pg 31
User Interface
The 262 uses a Liquid Crystal Display (LCD) as the method of supplying information. You use the LCD in order to setup and monitor
the operation of your system. The 262 uses four push buttons (Menu, Item, , ) for selecting and adjusting settings. As you program
your control, record your settings in the actual settings column of the Adjust Menu. The table is found in the second half of this brochure.
Menu
All of the items displayed by the control are organized into various menus. These menus are
listed on the left hand side of the display (Menu Field). To select a menu, use the
button. By pressing and releasing the
available menu. Once a menu is selected, there will be a group of items that can be viewed
within that menu.
Item
The abbreviated name of the selected item will be displayed in the item field of the display.
To view the next available item, press and release the
the last available item in a menu, pressing and releasing the
display to the first item in the selected menu.
Adjust
To make an adjustment to a setting in the control, begin by selecting the appropriate menu
using the
and / or button to make the adjustment.
Additional information can be gained by observing the Status field of the LCD. The status field will indicate which of the control’s outputs
are currently active. Most symbols in the status field are only visible when the View Menu is selected.
Menu
button. Then select the desired item using the
Copyright © D 262 -12/08
Menu
button, the display will advance to the next
Item
button. Once you have reached
Item
button will return the
Item
button. Finally, use the
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Menu
Menu
Menu
Menu
Item
Item
Item
Display
ecafretnI resU
Item Field
Displays an abbreviated
name of the selected item
Menu Field
Displays the
current menu
Status Field
Displays the current
status of the control’s
inputs, outputs and
operation
View
Adjust
Monitor
Schd
Misc
Menu
12
Item
1
UnOcc
DHW
°F°
Number Field
Displays the current value
of the selected item
Boiler Demand
DHW Demand
C
min
sec
hr
Ovr
Setpoint Demand
WWSD
Minimum
Maximum
!
Buttons
Selects Menus, Items and
{
adjusts settings
Symbol Description
Burner
Displays when the stage 1 and / or stage 2
1 2
relay is turned on.
1
DHW
UnOcc
Occ
Pump
Displays when the boiler pump is operating.
DHW Pump
Displays when the DHW pump is on.
Boost
Displays when the control is in boost after
setback.
UnOccupied Schedule
Displays when the control is in unoccupied
mode.
Occupied Schedule
Displays when the control is in occupied mode.
Ovr
!
°
F, °C, sec,
min, hr
Override
Displays when the control is in override mode.
Warning
Displays when an error exists or when a limit
has been reached.
Lock - Unlock
Displays whether the access levels are locked
or unlocked.
°F, °C, sec, min, hr
Units of measurement.
Pointer
Displays the control operation as indicated by
the text.
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Copyright © D 262 -12/08
Sequence of Operation
Boiler
Sensor
P
DHW
Pump
Boiler
Pump
Section A
General Operation
Section B
Boiler Reset
Section C
Domestic Hot
Section D
Setpoint
Water (DHW)
Page 4 - 6
Page 6 - 10
Page 10 - 12
Page 12
Section A —General Operation
POWERING UP THE CONTROL
When the Boiler Control 262 is powered up, the control displays the control type number in the LCD for 2 seconds. Next, the software
version is displayed for 2 seconds. Finally, the control enters into the normal operating mode and the LCD defaults to displaying the
current outdoor air temperature.
MODES OF OPERATION (MODE)
The Boiler Control 262 has two operating modes. The mode of operation
for which the control is to operate is selected in the
Mode 1
(MODE = —1—)
Mode 1 is designed for one or two stages of Heating, Domestic Hot
Water (DHW), and Setpoint operation.
Mode 2
(MODE = —2—)
Mode 2 is designed for dedicated DHW operation. In this mode, the 262
controls one or two stages of heat for DHW generation (see Section C3
Dedicated DHW).
Adjust Menu
.
STAGING
The 262 controls up to two stages in order to supply the required target
temperature. After each stage is turned on in the firing sequence, the
control waits a minimum amount of time before turning on the next stage.
The minimum time between stages is the total of the fire delay (FIRE DLY)
setting plus the minimum inter-stage delay selected by the boiler mass
(Boil MASS) setting. After the minimum time delay between stages has
expired, the 262 examines the control error to determine when the next
stage is to fire. The control error is determined using Proportional, Integral,
and Derivative (PID) logic.
Proportional
- compares the actual supply temperature to the boiler target
(Boil TRG) temperature. The colder the supply water temperature, the
sooner the next stage is turned on.
Integral
- compares the actual supply temperature to the Boil TRG
temperature over a period of time.
Derivative
- determines how fast or slow the supply water temperature is
changing. If the supply temperature is increasing slowly, the next stage is
turned on sooner. If the supply temperature is increasing quickly, the next
stage is turned on later, if at all.
Each stage has a minimum on time and a minimum off time.
FIRE DELAY (FIRE DLY)
The Fire Delay is the delay time that may occur between the time that the
262 closes a stage contact and the burner fires for that stage. This delay
is usually the result of burner pre-purge or other forms of time delay built
into the burner’s safety circuits.
BOILER MASS (Boil MASS)
The Boiler Mass setting allows the installer to adjust the control to the
thermal mass of different types of heat sources used.
Boiler Contact Closes
Boiler #1
Boiler Temperature
Fire
Delay
Boiler Contact Closes
Fire
Delay
Boiler Temperature
Interstage Delay
Boiler #1 Fires
Boiler Fires
Minimum On Time
Time
Fire
Delay
Minimum
Time
Boiler #2
Off Time
Boiler #2 Fires
Minim
Fire
Delay
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(LITE)
Light
The LITE setting is selected if the boiler(s) that is used has a low thermal mass. This means that the boiler(s) has a very small water
content and has very little metal in the heat exchanger. A boiler that has a low thermal mass comes up to temperature quite rapidly
when fired. This is typical of many copper fin-tube boilers. The minimum inter-stage delay for the LITE setting is two minutes.
Medium
The Medium setting is selected if the boiler(s) that is used has a medium thermal mass. This means that the boiler(s) either has a
large water content and a low metal content or a low water content and a high metal content. This is typical of many modern residential
cast iron boilers or steel tube boilers. The minimum inter-stage delay for the MED setting is four minutes.
Heavy
The Heavy setting is selected if the boiler(s) that is used has a high thermal mass. This means that the boiler(s) has both a large water
content and a large metal content. A boiler that has a high thermal mass is relatively slow in coming up to temperature. This is typical
of many commercial cast iron and steel tube boilers. The minimum inter-stage delay setting for the HEVY setting is six minutes.
BOILER DIFFERENTIAL (BOIL DIFF)
An on / off heat source must be operated with a differential in order to prevent short cycling. With the 262, either a fixed or an auto
differential maybe selected.
Fixed Differential
The boiler differential is divided around the Boil TRG temperature. The
first stage contact will close when the supply water temperature is 1/2 of
the differential setting below the Boil TRG temperature, and will open
when the supply water temperature is 1/2 of the differential setting above
the Boil TRG temperature. The second stage operates if the first stage
cannot bring the water temperature up to the Boil TRG temperature.
Auto Differential
If the Auto Differential is selected, the 262 automatically determines the
best differential as the load changes. This reduces potential short
cycling during light loads.
(MED)
(HEVY)
(AUTO)
Off
Differential
Time
On
Heating Load
Sequence, Section A
STAGE 1&2 (STAGE)
The stage 1 and 2 setting may be selected to AUTO or OFF. When AUTO
is selected, the stage is activated and the control operates the appropriate
boiler. When OFF is selected, the control does not fire the stage.
ROTATION (ROTATE)
The ROTATE item is an adjustable setting that is factory set at 48 hours.
The firing order of the boilers changes whenever one stage’s accumulated
running time exceeds the other stage’s accumulated running time by more
than the ROTATE setting. After each rotation, the stage with the least
running hours is the first to fire and the stage with the most running hours
is the last to fire. This function ensures that both stages receive equal
amounts of use. When this item is set to the OFF setting, Stage 1 is always
the first stage to fire.
BOILER PURGE (PURGE)
After the boiler demand is satisfied, the 262 continues to operate the boiler
pump (
Boil P1
, terminal 8) for a period of time. The length of time that the
boiler pump continues to run is adjustable (PURGE). This setting allows
purging of any excess heat out of the boiler after the burner is shut off. This
also helps to prevent the water in the boiler from flashing into steam after
the boiler is shut off. The boiler pump continues to run either until the
purging time has elapsed or the boiler supply (Boil SUP) temperature
drops more than a differential below the boiler minimum (Boil MIN) setting.
SETBACK (UNOCCUPIED)
To provide greater energy savings, the 262 has 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 water temperature, air temperature in the space
can be reduced even when thermostat(s) are not turned down. This feature is enabled by setting the
Setback
Note: AWAY does not require the DIP switch = Setback.
position, and providing either an external signal or an internal override.
1
720 hours
2
672 hours
672 hours
720 hours
Setback / None DIP
2
1
or
switch to the
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Copyright © D 262 -12/08
External Unoccupied
An external signal can place the 262 into an UnOccupied mode. Any time the
Com Sen
and the
mode. When in the UnOccupied mode, the
262 adjusts the supply water temperature based on the
(19) terminals are shorted together, the control operates in the UnOccupied
UnOcc
segment is displayed in the LCD. The
UnOcc
setting made in the control.
UnO Sw
(18)
18
UnO
Sw
19
Com
Internal Overrides
The 262 has a number of setback overrides that are selected through the
. These setback overrides have priority over any external setback signal. Any time an
Menu
override is in effect, the
(OVERRIDE)
Ovr
segment is displayed in the LCD.
Schedule (Schd)
Timer Switch
Temporary (TMPY)
If a temporary OVERRIDE is selected, the 262 operates in the selected override mode for
3 hours. Once over, the control reverts to the previous operation.
Permanent (PERM)
If a permanent OVERRIDE is selected, the 262 operates in the selected override mode
until a new OVERRIDE is selected.
Schd
UnOcc
Ovr
Away (AWAY)
If the AWAY override is selected, the 262 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
EXERCISING (EXERCISE)
The 262 has a built in pump exercising function. The exercising period setting is adjustable and is factory set at 70 hours. If a pump output
on the control has not been operated at least once during every exercising period, the control turns on the output for 10 seconds. This
minimizes the possibility of the pump seizing during a long period of inactivity.
Note: The exercising function does not work if power to the control or pump(s) is disconnected.
override.
Section B —Boiler Reset (Mode = —1—)
Section B1
General Boiler
Operation
Section B2
Alternate Boiler
Demands
Section B1 —General Boiler Operation
BOILER DEMAND
A boiler demand is generated by applying a voltage between 24 and 240 V (ac) across the
applied, the
boiler pump and the control turns on the boiler pump segment in the LCD. The 262 calculates a Boil TRG supply temperature based
on the outdoor air temperature and settings. The 262 then fires the boiler(s), if required, to maintain the target supply temperature.
Boiler Demand
pointer is displayed in the LCD. If the 262 is not in WWSD, it closes the
CHARACTERIZED HEATING CURVE OR RESET RATIO
The 262 has two methods of varying the supply water temperature based on the outdoor air temperature. The installer can select either
a
Characterized Heating Curve
Characterized Heating Curve
The
Characterized Heating Curve
temperature and optionally indoor temperature. The control takes into account the type of terminal unit that the system is using. Since
different types of terminal units transfer heat to a space using different proportions of radiation, convection and conduction, the supply
water temperature must be controlled differently. Once the control is told what type of terminal unit is used, the control varies the supply
water temperature according to the type of terminal unit. This improves the control of the air temperature in the building.
Reset Ratio
The
not take into account the type of terminal unit that the heating system is using and therefore is not as accurate as a
Heating Curve
Reset Ratio
method of controlling the supply water temperature is based solely on the outdoor air temperature. This method does
.
or a
Reset Ratio
.
is the most accurate method of controlling the supply water temperature based on outdoor air
Boil Dem
(1&2) terminals. Once voltage is
Boil P1
contact, which starts the
Characterized
Copyright © D 262 -12/08
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BOILER START (Boil STRT)
(
RESET RATIO
)
The Boil STRT temperature is the boiler supply water temperature that the
heating system requires when the outdoor air temperature equals the
OUT STRT air temperature setting.
OUTDOOR START (OUT STRT)
(
RESET RATIO
)
The OUT STRT temperature is the outdoor air temperature at which the
control provides the Boil STRT supply water temperature
OUTDOOR DESIGN (OUT DSGN)
(
RESET RATIO
&
CHARACTERIZED HEATING CURVE
)
to the system.
The OUT DSGN is the outdoor air temperature that is the typical coldest
temperature of the year where the building is located. This temperature is
used when doing heat loss calculations for the building.
BOILER DESIGN (Boil DSGN)
(
RESET RATIO
&
CHARACTERIZED HEATING CURVE
)
The Boil DSGN temperature is the supply water temperature required to
heat the boiler zones when the outdoor air is as cold as the OUT DSGN
temperature.
Boiler Reset
Ratio
Boil MIN
Boil STRT
OUT STRT
80
(27)
OUT DSGN
WWSD Occ
WWSD Unocc
60
(16)
40
(5)
Outdoor Air Temperature
Boil DSGN
Boil SETB
20
(-7)
Boil MAX
0
(-18)
-20
(-29)
210
(99)
190
(88)
170
(77)
150
(66)
130
(54)
110
(43)
90
(32)
70
(21)
Supply Water Temperature
Sequence, Section B1
BOILER MINIMUM (Boil MIN)
(
RESET RATIO
&
CHARACTERIZED HEATING CURVE
)
The Boil MIN is the lowest water temperature that the control is allowed to
use as a Boil TRG temperature. During mild conditions, if the 262 calculates
a Boil TRG temperature that is below the Boil MIN setting, the Boil TRG
temperature is adjusted to at least the Boil MIN setting. During this
condition, if the boiler is operating, the
Minimum
pointer turns on in the LCD
while the Boil TRG or the Boil SUP temperature is viewed. If the installed
boiler(s) is designed for condensing operation, set the Boil MIN adjustment
to OFF.
BOILER MAXIMUM (Boil MAX)
(
RESET RATIO
&
CHARACTERIZED HEATING CURVE
)
The Boil MAX is the highest water temperature that the control is allowed to
use as a Boil TRG temperature. If the control does target Boil MAX, and the
Boil SUP temperature is near the Boil MAX temperature, the
Maximum
pointer turns on in the LCD while the Boil TRG or the Boil SUP temperature is
viewed. At no time does the control operate the boiler(s) above 248˚F (120˚C).
WARM WEATHER SHUT DOWN (WWSD) OCC & UNOCC
(
RESET RATIO
&
CHARACTERIZED HEATING CURVE
)
When the outdoor air temperature rises above the WWSD setting, the 262
turns on the
Weather Shut Down, the
WWSD
pointer in the display. When the control is in Warm
Boiler Demand
pointer is displayed if there is a
demand. However, the control does not operate the heating system to
satisfy this demand. The control does respond to either a
or a
Setpoint Demand
BOILER SETBACK (SETBACK)
and operates as described in Section C.
(
RESET RATIO
)
DHW Demand
The boiler SETBACK is the amount that the boiler supply water temperature
is reduced when the 262 is placed into an
UnOccupied
mode, using an
internal or an external setback as described in Section A. This setting is
only available if the
DIP switch is set to
BOILER INDOOR (Boil INDR)
(
CHARACTERIZED HEATING CURVE
Reset Ratio
Setback
.
DIP switch is selected and
)
Setback / None
The Boil INDR is the room temperature used in the heat loss calculations
done for the building. This setting establishes the beginning of the
terized Heating Curve
for the boiler zones. This single setting replaces the
Charac-
Boil STRT water temperature and OUT STRT air temperature settings used
by the
Reset Ratio
.
Boil Min + 1/2 Boiler Differential
e
T
r
e
t
a
W
l
i
B
o
Pointer On
l
i
B
o
Pointer On
Boiler Characterized
Heating Curve
Boil MIN
Boil IND
Boil ROOM Occ
80
(27)
60
(16)
(5)
Outdoor Air Temperature
e
r
u
t
a
er
p
m
Boil Min - 1/2 Boiler Differential
Boil Max + 1/2 Boiler Differential
r
u
t
a
r
e
p
m
e
T
r
e
t
a
W
Boil Max - 1/2 Boiler Differential
Boil MIN
e
Pointer On
Boil DSGN
OUT DSGN
WWSD Occ
WWSD Unocc
Boil ROOM UnOcc
40
20
(-7)
0
(-18)
Boil MAX
Boil MAX
-20
(-29)
210
(99)
190
(88)
170
(77)
150
(66)
130
(54)
110
(43)
90
(32)
70
(21)
50
(10)
Supply Water Temperature
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Copyright © D 262 -12/08
ROOM OCC & UNOCC (ROOM)
(
CHARACTERIZED HEATING CURVE
The ROOM is the desired room temperature for the boiler zone(s) and it provides a parallel shift of the
The room temperature desired by the occupants is often different from the designed indoor temperature (Boil INDR). If the room
temperature is not correct, adjusting the ROOM setting increases or decreases the amount of heat available to the building. If the
Setback / None
DIP switch is set to
)
Characterized Heating Curve
Setback
, a ROOM setting must be made for both the
Occupied
and
UnOccupied
modes.
.
TERMINAL UNITS (TERMINAL)
When using a
unit. The terminal unit determines the shape of the
to how the terminal unit delivers heat into the building space. The 262 provides for selection
between six different terminal unit types: two types of hydronic radiant floor heat, fancoil, fin–
tube convector, radiator, and baseboard.
Characterized Heating Curve
Hydronic Radiant Floor
HRF 1 is a heavy, or high mass, hydronic radiant floor system. This type of a hydronic radiant
floor is embedded in either a thick concrete or gypsum pour. This heating system has a large
thermal mass and is slow acting.
Hydronic Radiant Floor
HRF 2 is a light, or low mass, hydronic radiant floor system. Most commonly, this type of
radiant heating system is either attached to the bottom of a wood sub floor, suspended in
the joist space, or sandwiched between the subfloor and the surface. This type of radiant
system has a relatively low thermal mass and responds faster than a high mass system.
Fancoil
A fancoil terminal unit or air handling unit (AHU) consists of an hydronic heating coil and
either a fan or blower. Air is forced across the coil at a constant velocity by the fan or blower
and is then delivered into the building space.
Fin-tube Convector
A convector terminal unit is made up of a heating element encased in fins. 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.
(COIL)
(CONV)
(HRF 1)
(HRF 2)
, the control requires the selection of a terminal
Characterized Heating Curve
according
HRF 1
HRF 2
COIL
CONV
Radiator
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
A baseboard terminal unit is similar to a radiator, but has a low profile and is installed at the
base of the wall. The amount of heat transferred by radiation from a baseboard is greater
than that from a fin-tube convector.
BOILER TARGET TEMPERATURE (BOIL TRG)
(
RESET RATIO
The Boil TRG temperature is determined from either the
temperature and optionally indoor temperature feed back. The control displays the temperature that it is currently trying to maintain as
the boiler supply temperature. If the control does not presently have a requirement for heat, it displays “- - -” in the LCD.
BOILER OPERATION
When the 262 determines that boiler operation is required, the
Boiler contact(s) is closed, the burner and stage segment in the LCD is displayed.
BOILER PUMP (P1) OPERATION
The
Boiler Pump
the control receives a boiler demand and the Boil TRG temperature is below the Boil MIN setting, the boiler pump may continue to operate
after the boiler demand is removed. For boiler pump contact operation during either DHW and / or Setpoint operation, refer to the DHW,
and Setpoint Section D.
Soft Start
The SOF STRT function allows the 262 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.
Copyright © D 262 -12/08
(RAD)
(BASE)
&
CHARACTERIZED HEATING CURVE
)
contact (P1, terminal 8) closes whenever there is a
(SOF STRT)
Characterized Heating Curve
Boiler stage contact(s)
Boiler demand
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and the 262 is not in WWSD. If 10K = INDR or SLAB,
RAD
BASE
or the
Reset Ratio
(11 and 12 and/or 13 and 14) close. While the
settings and the outdoor air
Boosting
(BOOST)
When the control changes from the
it enters into a
Boosting
UnOccupied
to the
Occupied
mode,
mode. In this mode, the supply water temperature 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
setting is only available if a
is not available for a
Typical settings for the
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
is selected in the user interface. This
Characterized Heating Curve
Reset Ratio
Boost
or if a tekmar Zone Control is used.
function vary between 30 minutes and two
Boost
time is selected, the
is selected; It
Water Temperature
UnOcc to Occ
setback timer must be adjusted to come out of setback some time in
Boost
Occupied
setting.
advance of the desired
the same as the
If the building is not up to temperature at the correct time, the
time. This time in advance is normally
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
Boil TRG
Boil TRG
Boost setting - 20 minutes to 8 hours
Boost
Boost
(Occupied)
Self Adjusting
Water Temperature
(UnOccupied)
Time
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
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
power must be applied to the
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
Boiler Demand
.
Com
and
10K
Boiler Demand
setting in the Adjust menu at the control.
terminals (1 and 2) as described in Section B1.
terminals (16 and 17). In addition,
tekmar
Indoor Sensor
tekmar
262 Control
Boiler Demand
Vie
DHW Demand
°
F
Setpoint Demand
WWSD
Occ
Minimum
1
Maximum
2
1
Item
Menu
Boiler Control 262
Two Stage Boiler & DHW / Two Stage DHW
NRTL/C
LR 58223
R
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
(16 and 17) of the 262. The zone control provides its own internal
In this case, there is no need to provide an external
Boiler Demand
Com
and
10K
terminals
Boiler Demand
to the 262.
as described earlier in
tekmar
Zone Control
Power
Occupied
UnOccupied
Heat Required
Optimum Start / Stop
24 hr. Timer
System Pump
Timer Active
70°F
(21°C)
12 hrs.
Zone 1 / Lo stage /
1
Open / Cooling
• Dial the desired duration
618
of the UnOccupied period.
Zone 2 / Hi stage /
• Press start button at the time of day
2
Close / Ventilation
you want the UnOcc. period to begin.
Zone 3 / Lo stage
Timer Active light turns on.
3
Open
0
24
40
100
Zone 4 / Hi stage
(4)
(38)
UnOccupied
4
Close
UnOccupied
Duration
Zone 5 / Lo stage
5
Start
Open
Zone 6 / Hi stage
6
Close
0 = always Occupied
24 = always UnOccupied
Zone Control 367
One & Two Stage / One Stage & Floating
tekmar
262 Control
Boiler Demand
Vie
DHW Demand
°
F
Setpoint Demand
WWSD
Occ
Minimum
1
Maximum
2
1
Item
Menu
Boiler Control 262
NRTL/C
Two Stage Boiler & DHW / Two Stage DHW
LR 58233
E150539
LR 58223
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
applied to the
sensor connected, the 262 will limit the supply temperature in order to maintain the slab sensor
Boiler Demand
Com
and the
terminals (1 and 2) as described in Section B1. With the slab
10K
terminals (16 and 17). Power must be
tekmar
Slab Sensor
tekmar
262 Control
Boiler Demand
Vie
DHW Demand
°
F
Setpoint Demand
WWSD
Occ
Minimum
1
Maximum
2
1
Item
Menu
Boiler Control 262
Two Stage Boiler & DHW / Two Stage DHW
NRTL/C
LR 58223
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
Slab Max
(SLAB MAX)
Schedule
menu, the 262 ignores the SLAB MIN setting.
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 NetTM
tN1 / tN2
terminals (15 and 16). In addition, power must be applied to the
Boiler Demand
terminals (1 and
R
R
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Copyright © D 262 -12/08
2) as described in Section B1. With the RTU connected, the 262 measures the actual ROOM temperature. Indoor temperature feedback
fine tunes the supply water temperature in the system to prevent over heating or under heating. The RTU allows the user to adjust the
desired room temperature at the RTU. Remote sensor capability is also available through an RTU. See the Data brochure for the RTU
you are connecting.
Section C —Domestic Hot Water (DHW) and Setpoint (Mode = —1—)
Section C1
General Domestic
Hot Water (DHW)
Operation
Section C2
DHW Priority
Section C3
DHW with Low
Temperature
Boilers
Section C4
Dedicated
DHW
Section C1 —General Domestic Hot Water (DHW) Operation (Mode = —1—)
DHW DEMAND
A
DHW demand
demand from an aquastat or an internal demand from a 10K tekmar sensor. If an external and
internal demand is present simultaneously, the control stops operation of the DHW.
External Demand
The 262 registers an external demand for DHW when a voltage between 24 and 240 V (ac)
is applied across the
or setpoint control is used as a switch in the DHW demand circuit. Once the 262 detects a
DHW demand, the
described below.
Internal Demand
The 262 registers an internal demand for DHW when a sensor is connected across the
and the
indirect DHW tank temperature. When MODE –1– is selected, if the temperature at the DHW
sensor drops 3˚F (1.5˚C) below the DHW TANK setting, the
in the LCD and the control operates as described below.
An advantage to using the DHW sensor is that the control can display the current DHW TANK
temperature and record the highest and lowest DHW TANK temperatures. Also, the 262 can
control the DHW temperature with more accuracy than when using an aquastat.
is generated on the 262 by using one of two methods: either an external DHW
(DHW SENS = NONE)
Com Dem
DHW Demand
and the
pointer turns on in the LCD and the control operates as
(DHW SENS = DHW)
DHW
terminals (19 and 20). The DHW TANK setting is used to set the desired
DHW Dem
terminals (3 and 4). A DHW aquastat
DHW Demand
pointer turns on
Com
24 to 240 V (ac)
Aquastat
DHW
Storage Tank
Pump
P
Com
Dem
Com
3
19
4
DHW
Dem
20
DHW
DHW DEVICE (DHW THRU)
Once the 262 receives a
DHW device selected. The DHW device is selected using the DHW THRU item in the
menu.
DHW Pump
If PUMP is selected as the DHW device, the 262 assumes that the DHW pump provides
adequate flow through both the DHW tank heat exchanger and the boiler(s). To provide heat
to the DHW tank, the 262 closes the
boiler(s) to provide a sufficient boil supply temperature to the DHW tank. If using a primary
loop with the DHW tank piped in primary / secondary, select DHW VALV.
DHW Valve
If VALV is selected as the DHW device and there is a
Boil P1
The 262 operates the boiler(s) to provide a sufficient boiler supply temperature to the DHW tank.
(DHW THRU = PUMP)
(DHW THRU = VALV)
contact (7 and 8). The boiler pump provides flow through the DHW tank’s heat exchanger once the DHW valve is opened.
BOILER TARGET DURING DHW GENERATION (Boil TRG)
The Boil TRG temperature during DHW operation depends on whether an external or internal demand is present. The DHW demand
overrides the reset water temperature.
External Demand
If the control receives a
as the DHW heat exchanger setting (DHW XCHG).
Copyright © D 262 -12/08
(DHW SENS = NONE)
DHW Demand
DHW demand
, the sequence of operation depends on the type of
Adjust
P
DHW Pmp / Vlv
contact (9 and 10) and operates the
DHW Demand
, the 262 closes the
DHW Pmp / Vlv
Valve
contact (9 and 10) and the
through an external device such as an aquastat, the Boil TRG temperature is at least as hot
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Internal Demand
If the control receives a
Boil TRG temperature is at least as hot as the DHW TANK setting plus 40˚F (22˚C).
(DHW SENS = DHW)
DHW demand
from a DHW sensor attached to the
Com Sen
and the
DHW 10K
terminals (19 and 20), the
DHW DURING UNOCCUPIED
The DHW operation during an
that is being used. For this function to operate, the control must have the
External Demand
If an external
period or the control can ignore a call for DHW as long as the control is in an
Internal Demand
If an internal
as long as the control is in an
Away
If the AWAY setting is made in the
the DIP switch =
(Aquastat )
DHW Demand
(Sensor)
DHW Demand
Setback.
UnOccupied
period depends on the type of
is used, the control can either continue operation of the DHW system as it would during the
is used, a DHW TANK
UnOccupied
Schd
mode.
menu, any
Unocc
temperature can be set. This is the temperature that the tank maintains
DHW Demand
Section C2 —DHW Priority (Mode = —1—)
DHW PRIORITY (DHW PRI = BOIL)
It is often desirable to limit or even stop the flow of heat to the heating
system when the DHW tank calls for heat. This allows for a faster recovery
of the DHW tank. If DHW PRI is set to Boil, the boiler pump (P1) is turned
off on a call for DHW. This setting is available only if DHW THRU = PUMP
has been selected as the DHW device. If a valve is used as the DHW
device, DHW priority can not be used. Caution should be taken to ensure
that the flow rate of the DHW pump is adequate for both the DHW tank and
the boiler(s), as this will be the only pump providing flow through the
boiler(s).
DHW demand
Setback / None
that the 262 is receiving and the type of setback
DIP switch set to
Setback.
Occupied
UnOccupied
is ignored and the tank cools off. Note: AWAY does not require
mode.
P
DHW
P1
Sequence, Section C2
DHW PRIORITY OVERRIDE
To prevent the building from cooling off too much or the possibility of a
potential freeze up during DHW priority, the 262 limits the amount of time
for DHW priority. As the outdoor air temperature becomes colder, the
length of time that the 262 provides DHW priority is reduced. Once the
allowed time for priority has elapsed, the 262 overrides the DHW priority
and operates DHW and heating simultaneously.
CONDITIONAL DHW PRIORITY
If the boiler supply temperature is maintained at or above the required
temperature during DHW generation, this indicates that the boiler(s) has
enough capacity for DHW and possibly heating as well. As long as the
boiler supply temperature is maintained near its target, DHW and heating
occurs simultaneously.
DHW POST PURGE
After the
either the DHW pump or the DHW valve and the boiler pump. This purges the residual heat from the boiler(s) into the DHW tank. The
262 continues this purge for a maximum of four minutes or until the boiler supply water temperature drops 20˚F (11˚C) below the DHW
Boil TRG temperature. The 262 also stops the purge if the boiler supply temperature drops below the current Boil TRG temperature.
DHW Demand
DHW MIXING PURGE
After DHW operation, the boiler(s) is extremely hot. At the same time, the heating zones may
have cooled off considerably after being off for a period of time. To avoid thermally shocking
the boiler(s) after DHW priority, the 262 shuts off the boiler(s), but continues to operate the
DHW while restarting the heating system. This allows some of the DHW return water to mix
with the cool return water from the zones and temper the boiler return water.
Increasing Time
DHW priority demand time limit
Increasing Air Temperature
Outdoor air temperature
is removed, the 262 performs a purge on the boiler(s). The 262 shuts off the boiler(s) and continues to operate
P
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Copyright © D 262 -12/08
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