tekmar 256 User Manual

- Installation & Operation Manual

D 256

Boiler Control 256

07/11

The Boiler Control 256 is designed to control a single stage heat source in order to provide outdoor reset. The control has a Liquid Crystal Display (LCD) to view system status and operating information.

Additional functions include:

• Quick Setup for easy installation and programming of control

• User comfort adjustment to increase or decrease building space temperature

• Advanced settings to ﬁ ne-tune building requirements

Press & Release:

all 3 buttons, to adjust menu

Press & Hold:

Item, to view settings

, to test.

tektra 909-01

BOIL

• Test sequence to ensure proper boiler operation

• Setback input for energy savings

• CSA C US certiﬁ ed (approved to applicable UL standards)

Power: 24 V ±10% 50/60 Hz 3 VA Class 2 Relay: 240 V (ac) 5 A 1/6 hp

Meets Class B: Canadian ICES FCC Part 15

H1190D

Input

Universal Sensor

Included

Input

Outdoor Sensor

Included

Terminal Unit Boiler Demand

Item

Boiler Control 256

One Stage Boiler

Do not apply power

Boil2Out3Com4UnO

Inst / Adv

Input

tekmar Timer

Optional

TIME

PRGM

AMPM

UNOCC OVR

SMWTFT

OCC

Designed &

Assembled in

Canada Signal wiring must be rated at least 300V

Boiler

67T8

Output

Boiler

Power

R+

Date Code

C-

Input

24 V (ac)

Power Supply

Input

Boiler Demand

Signal

Note:

Boiler demand must have an electrical closure between terminals 7 and 9 before the boiler is able to fire.

How to Use the Data Brochure

This brochure is organized into four main sections. They are: 1) Sequence of Operation, 2) Installation, 3) Control Settings, and 4) Troubleshooting. The Sequence of Operation section has three sub-sections. We recommend reading Section A: General Operation

of the Sequence of Operation, as this contains important information on the overall operation of the control. Then read the sub-sections that apply to your installation. For quick installation and setup of the control, refer to the Installation section, DIP Switch Setting section, followed by the Quick Setup section.

The Control Settings section (starting at DIP Switch Setting) of this brochure, describes the various items that are adjusted and displayed by the control. The control functions of each adjustable item are described in the Sequence of Operation.

Table of Contents

User Interface ..................................................... pg 2

Description of Display Elements ....................... pg 3

Sequence of Operation ...................................... pg 4

Section A: General Operation ................ pg 4

Section B: Boiler Reset ......................... pg 5

Installation........................................................... pg 8

DIP Switch Setting .............................................pg 15

Quick Setup ........................................................pg 15

Reference Material: Essay E 003 “Characterized Heating Curve and Reset Ratio”

Control Settings .................................................pg 16

View Menu ...............................................pg 16

Adjust Menu ............................................pg 16

Testing and Troubleshooting............................pg 18

Error Messages .......................................pg 19

Technical Data ...................................................pg 19

Limited Warranty .............................................. pg 20

User Interface

The 256 uses a Liquid Crystal Display (LCD) as the method of supplying information. You use the LCD in order to set up and monitor the operation of your system. The 256 has three push buttons (Item, , ) for selecting, viewing, and adjusting settings. As you program your control, record your settings in the ADJUST menu table which is found in the second half of this brochure.

Item

The abbreviated name of the selected item will be displayed in the item ﬁ eld of the display. To view the next available item, press and release the Item button. Once you have reached the last available item, pressing and releasing the Item button will return the display to the ﬁ rst item.

Item

Adjust

To make an adjustment to a setting in the control, press and hold simultaneously for 1 second, all 3 buttons. The display will then show the word ADJUST in the top right corner. Then select the desired item using the Item button. Finally, use the and / or button to make the adjustment.

To exit the ADJUST menu, either select the ESC item and press the leave the adjustment buttons alone for 20 seconds.

When the Item button is pressed and held in the VIEW menu, the display scrolls through all the control adjust items in both access levels.

Additional information can be gained by observing the status ﬁ eld and pointers of the LCD. The status ﬁ eld will indicate which of the control’s outputs are currently active. Most symbols in the status ﬁ eld are only visible when the VIEW menu is selected.

or button, or

Item

Display

Item Field

Displays an abbreviated name of the selected item

OUTDR BOIL

ROOM WWSD INDR

Terminal Unit

Status Field

Displays the current status of the control’s inputs, outputs and operation

DSGN

TARGET

MAXMIN

OCC

Item

DIFF

Number Field

Displays the current value of the selected item

VIEW ADJUST

Boiler Demand

Buttons

Selects Menus, Items and

{

adjusts settings

Menu Field

Displays the current menu

Symbol Description

Burner

Displays when the boiler relay is turned on.

OCC

UNOCC

Occupied Schedule

Displays when the control is in occupied (Day) mode.

Unoccupied Schedule

Displays when the control is in unoccupied (Night) mode.

F, °C

°F, °C

Displays the unit of measure that all of the temperatures are to be displayed in the control.

Pointer

Displays the control operation as indicated by the text.

Sequence of Operation

Section A

General Operation

Page 4

Section B

Boiler Reset

Page 5-8

Section A — General Operation

POWERING UP THE CONTROL

When the Boiler Control 256 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.

OPERATION

The 256 operates a single on / off heat source to control the supply water temperature to a hydronic system. The supply water temperature is based on the current outdoor air temperature and the Characterized Heating Curve settings.

Terminal Unit

Indoor Design

Decreasing Outdoor Temperature

Outdoor Design

Design Supply

Increasing Water Temperature

SETBACK (UNOCCUPIED)

To provide greater energy savings, the 256 has a setback capability. With setback, the supply water temperature in the system is reduced 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. Any time the Com (3) and the UnO Sw (4) terminals are shorted together, the control operates in the unoccupied (Night) mode. When in the unoccupied (Night) mode, the UNOCC segment is displayed in the LCD. The 256 adjusts the supply water temperature based on the UNOCC settings made in the control.

FACTORY DEFAULTS

The control comes preset with several factory defaults. These defaults are based on the terminal unit selection (see section B2). To ﬁ ne-tune building requirements, these defaults may be changed. If a factory default value for a terminal unit is changed, the terminal unit number will ﬂ ash when selected in the ADJUST menu.

To reload the factory defaults listed in section B2, power down the control and wait for 10 seconds. Power up the control while simultaneously holding the Item and buttons. The terminal unit number should now be displayed constantly in the LCD rather than ﬂ ashing.

Com

UnO

Timer switch

Section B: Boiler Reset

Section B1

General

Section B2

Installer

Section B3

Advanced

Section B1: General

Power

R+

C-

BOILER DEMAND

A boiler demand is required in order for the 256 to provide heat to the heating system. A boiler demand is generated by connecting terminal T(7) to terminal C-(9) through a switching device. Once the switching device closes, the Boiler Demand pointer is displayed in the LCD. The 256 calculates a BOIL TARGET supply temperature based on the outdoor air temperature and settings.

BOILER OPERATION

When the 256 determines that boiler operation is required, the Boiler contact terminals (5 and 6) close. While the Boiler contact is closed, the burner segment in the LCD is displayed.

24 V (ac)

Boiler demand switches

CHARACTERIZED HEATING CURVE

The 256 varies the supply water temperature based on the outdoor air 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.

BOILER TARGET TEMPERATURE (BOIL TARGET)

The BOIL TARGET temperature is determined from the Characterized Heating Curve settings and the outdoor air temperature. 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 does not show a boiler target temperature. Instead, “- - -” is displayed in the LCD. At no time does the control operate the boiler above 248°F (120°C).

Section B2: Installer

OUTDOOR DESIGN (OUTDR DSGN)

The OUTDR 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 the heat loss calculations for the building. If a cold outdoor design temperature is selected, the boiler supply temperature rises gradually as the outdoor temperature drops. If a warm outdoor design temperature is selected, the boiler supply temperature rises rapidly as the outdoor temperature drops.

ROOM OCC & UNOCC (ROOM)

The ROOM is the desired room temperature for the boiler zones, and it provides a parallel shift of the Characterized Heating Curve. The room temperature desired by the occupants is often different from the design 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. A ROOM setting is available for both the occupied (Day) and unoccupied (Night) modes.

TERMINAL UNITS

When using a Characterized Heating Curve, the control requires the selection of a terminal unit. The terminal unit determines the shape of the Characterized Heating Curve according to how the terminal unit delivers heat into the building space (refer to Essay E 003). The 256 provides for selection between six different terminal unit types: two types of radiant ﬂ oor heat, fancoil, ﬁ n-tube convector, radiator and baseboard. When a terminal unit is selected, the control automatically loads the design supply temperature (BOIL DSGN) and minimum supply temperature (BOIL MIN). The factory defaults are listed below. To change defaults, refer to section B3. If a default has been changed, refer to section A to reload the factory defaults.

Terminal Unit

BOIL DSGN 120°F (49°C) 140°F (60°C) 190°F (88°C) 180°F (82°C) 160°F (71°C) 150°F (66°C)

BOIL MIN OFF OFF 140°F (60°C) 140°F(60°C) 140°F (60°C) 140°F (60°C)

High Mass Radiant (1)

This type of a hydronic radiant ﬂ oor is embedded in either a thick concrete or gypsum pour. This heating system has a large thermal mass and is slow acting. Default values: BOIL DSGN = 120°F (49°C), BOIL MIN = OFF

Low Mass Radiant (2)

This type of radiant heating system is either attached to the bottom of a wood sub-ﬂ oor, suspended in the joist space, or sandwiched between the sub-ﬂ oor and the surface. This type of radiant system has a relatively low thermal mass and responds faster than a high mass system. Default values: BOIL DSGN = 140°F (60°C), BOIL MIN = OFF

High Mass Radiant

(1)

Low Mass Radiant

(2)

Fancoil

(3)

Fin-tube Convector

(4)

Radiator

(5)

Baseboard

(6)

Fancoil (3)

A fancoil terminal unit or air handling unit (AHU) consists of a 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. Default values: BOIL DSGN = 190°F (88°C), BOIL MIN = 140°F (60°C)

Fin–tube Convector (4)

A convector terminal unit is made up of a heating element with ﬁ ns 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 to the space is dependant on the supply water temperature to the heating element and the room air temperature. Default values: BOIL DSGN = 180°F (82°C), BOIL MIN = 140°F (60°C)

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