tekmar 279 User Manual

- Data Brochure

Steam Control 279

D 279

05/10

The tekmar Steam Control 279 can operate a single on-off steam boiler or an on-off steam valve using outdoor reset. The

control determines the on time of the boiler or valve based on the measured outdoor temperature and settings entered by the installer. A large LCD displays the current status and operating temperatures.

Additional functions include:

•

CSA approved for use in USA and Canada

•

Outdoor Reset

•

Manual Override

•

Includes Outdoor Sensor

•

Includes Condensate Sensor

•

Large LCD Display Optional Indoor Sensors

•

DHW Tankless Coil Operation

•

Warm Weather Shut Down

•

Built-in Programmable Timer

•

24 Hour, 5-1-1, 7 Day Schedule

•

Two or Four Schedule Events Per Day

•

Two Alert Level Relays

Input

115 V (ac)

Power Supply

Menu Item

Steam Control 279

One Stage

2N3

Power

Alert 1 Boiler

STATUS Establishing Steam Heat Cycle Lockout Differential DHW Tankless Coil Heating

6785

Alert 2

LowHigh

Average Indoor S2 Indoor S1

Installer

User

Condensate Sensor DHW Tankless Coil Sensor Setback

Oﬀ

Test

oﬀ red red

For manual operation, press and hold Test button for 3 seconds.

Com Sen

Meets Class B: Canadian ICES FCC Part 15

Out

Cdn

Sen

Made in Canada By tekmar Control Systems Ltd. tektra 969-04

Power 115 V ±10% 50/60 Hz 3.5 VA Relays 230 V (ac) 5 A 1/3 hp, pilot duty 240 VA

Signal wiring must be rated at least 300 V.

Do not apply power

Com Sen

DHW

Sen

Indr

not testing testing testing paused

Date Code

H2046A

Input

Outdoor Sensor

Included

Output

High Priority

Alert

Output

Low Priority

Alert

Output

Boiler or On/Off

Steam Valve

Input

Universal Sensor

Optional

Input

Indoor Sensor

Optional

Input

Indoor Sensor

Optional

Input

Universal Sensor

Included

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) Testing and Troubleshooting. The Sequence of Operation section has fourteen sub-sections. We recommend reading ‘Section A: General’ 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.

Table of Contents

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

Display and Symbol Description ...................................3

Definitions .....................................................................4

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

General ................................................................. 4

Establishing Steam ...............................................4

Heating Cycle .......................................................6

Lockout Differential ...............................................7

Optional Indoor Sensors .......................................8

Built-in Timer ........................................................8

Programmable Schedule ......................................8

Warm Weather Shut Down ...................................8

Optimum Start ......................................................9

Boost ....................................................................9

Limited Occupied ..................................................9

The Control Settings section (starting at Switch Settings) 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.

Alert Relay Operation ...........................................9

Domestic Hot Water Tankless Coil ..................... 10

Installation .................................................................. 10

Cleaning the Control ................................................... 14

Switch Settings ........................................................... 15

Display Menus ............................................................ 16

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

Adjust Menu ........................................................ 17

Time Menu .......................................................... 19

Schedule Menu ................................................... 20

Testing the Control ......................................................20

Troubleshooting .......................................................... 21

Error Messages ..........................................................22

Technical Data ............................................................ 24

Limited Warranty ........................................................24

User Interface

The control uses a Liquid Crystal Display (LCD) as the method of supplying information. Use the LCD in order to setup and monitor the operation of the system. The control has four push buttons (Menu, Item, , ) for selecting and adjusting settings. As the control is programmed, record the settings in the ADJUST Menu table which is found in the second half of this brochure.

All of the items displayed by the control are organized into four menus: View, Adjust, Time, and Schedule. These menus are listed on the top of the display (Menu Field). To select a menu, use the Menu button. By pressing and releasing the Menu button, the display will advance to the next available menu. Once a menu is selected, there will be a group of items that can be viewed within the menu.

Note: The TIME and SCHEDULE menus are not available when Setback is turned off.

Menu Item

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 Item button. Once you have reached the last available item in a menu, pressing and releasing the Item button will return the display to the first item in the selected menu.

The items can be quickly scrolled through by holding the Item button and then pressing the button. To rapidly scroll through the items in the reverse order, hold the Item button and press the button.

Menu Item

Adjust

To make an adjustment to a setting in the control, begin by selecting the appropriate menu using the Menu button. Then select the desired item using the Item button. Finally, use 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 Item

Display

°°F°

Menu Field

Displays the

current menu

Item Field

Displays the current

item selected.

Buttons

Selects Menus, Items

and adjusts settings

Symbol Description

Number Field

Displays the current value of the selected item

Menu Item

Status Field

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

STATUS Establishing Steam Heat Cycle Lockout Differential DHW Tankless Coil Heating

POINTER

Displays the control operation as indicated by the text.

°F, °C

Units of measurement.

OCCUPIED SCHEDULE

Displays when the control is in the Occupied event period.

UNOCCUPIED SCHEDULE

Displays when the control is in the Unoccupied event period.

BURNER

Displays when the boiler contact is turned on.

WARNING 1 2

Displays when an error exists or when a limit has been reached. A 1 indicates a high level alert, a 2 indicates a low level alert.

USER ACCESS LEVEL

Displays when the Installer/User Switch Setting is set to the User access level.

STEAM ESTABLISHED

Displays once the condensate sensor reaches a temperature sufficient for steam to reach the furthest radiator.

BOOST

Displays while the boost feature extends the boiler on time to allow recovery after night setback.

OPTIMUM START

Displays while the Optimum Start feature extends the boiler on time to allow recovery after night setback.

WWSD

Displays while the control is in Warm Weather Shut Down.

STATUS Establishing Steam

Deﬁ nitions

The following defined terms and symbols are used throughout this manual to bring attention to the presence of hazards of various risk levels, or to important information concerning the life of the product.

Caution: Refer to accompanying documents.

Sequence of Operation

General Section A

Powering up the control

When the control is powered on, all segments in the LCD are turned on for 2 seconds. Next, the control displays the control type number in the LCD for 2 seconds. Next, the software version is displayed for 2 seconds. Last, the control enters into the normal operating mode.

Boiler Contact Operation

In single on-off steam boiler applications, the control uses the boiler contact to connect to the thermostat terminals (T-T) on the boiler. The pressure control and all other safety devices and circuits must continue to be wired in series to the burner circuit. The boiler contact on the control is used to turn on or off the steam boiler burner.

In steam valve applications, the boiler contact on the control is used to power the valve motor to open the valve. When power is removed, the valve must close.

Status

The control has a status field on the right hand side of the control. A pointer is shown in the status field once the boiler contact is turned on. The pointer indicates at which point of the steam heating system cycle the control is currently operating at.

The steps are as follows:

Establishing Steam

•

Heat Cycle

•

Lockout Differential

•

DHW Tankless Coil Heating

•

STATUS Establishing Steam Heat Cycle Lockout Differential DHW Tankless Coil Heating

Each of these steps are described in detail in the following sections.

Establishing Steam Section B

In steam heating systems, there is a time delay between when the steam boiler or steam valve is turned on and when the steam finally reaches the furthest radiator in the system. It is important for the control to determine how long this time delay is in order to ensure proper heating in all rooms. When heat is required, the control activates the boiler relay but does not consider the heating cycle to start until steam has been established at the furthest radiator. While the control is waiting to establish steam, the Status field will have a pointer indicating Establishing Steam.

The control can use one of two methods to determine the time to establish steam.

Condensate Return Sensor

The Universal Sensor 071 included with the control can be used to measure the temperature of the condensate return pipe. In a one pipe system, it is recommended to install the sensor on the bottom of the pipe just before it enters the last radiator. In a two pipe system, it is recommended to install the Condensate Sensor on the bottom of the condensate return pipe of the radiator furthest from the boiler. In cases where access to the furthest radiator is not possible, an alternative is to locate the sensor on the bottom of the condensate return pipe in the mechanical room. Once the condensate sensor is installed, ensure the Condensate Sensor/Off Switch Setting to Condensate Sensor. The measured condensate return temperature reading is visible in the View menu.

The Adjust menu includes a Steam Established setting that

Establishing Steam

(warm-up period)

Establishing Steam

(warm-up period)

delays the start of the heating cycle until the condensate sensor has reached a set temperature.

One method to set the Steam Established setting requires two people with two-way radios. One person is at the control location; the other person is at the furthest radiator

One Pipe System:

Last Radiator

location. The steam system can be manually started using the Max Heat feature. Once the furthest radiator starts to get steam, exit the Max Heat feature and view the Condensate temperature in the View menu. The measured condensate return temperature can be entered as the Steam Established setting.

Most Distant Radiator

Two Pipe System:

Main

Air Vent

Condensate Return Sensor Location

Off

Boiler

Operation

220°F 210°F 200°F 190°F 180°F 170°F 160°F -

Condensate Return

Temperature

150°F 140°F -

Best

(warm-up period)

Establishing Steam

Supply Main

15 minutes

on time

est.

Steam established

temperature setting

Thermostatic

Radiator Vent

Return

Air Vent

Steam established - start cycle

Boiler OffBoiler On

60 minute cycle 60 minute cycle

off

Boiler On

15 minutes

on time

(warm-up period)

Establishing Steam

est.

Tra p

Best

Supply

Air Vent

Float &

Thermostatic

Tra p

Condensate Return

Sensor Location

Boiler Off

Steam established - start cycle

45 minutes off time45 minutes off time

off

25% on time with Condensate Return Sensor and ‘Steam Established’ set to 170°F

Minimum On Time

In cases where a condensate return sensor cannot be installed, a Minimum On Time can be set to account for the establishing steam time period. Setting a Minimum On Time for a steam system can be problematic because a system takes more time to reach operating temperature from a cold start than when it is hot from a previous cycle.

To set the Minimum On Time, manually start the steam system using the Max Heat feature and at the same time, start a stopwatch timer. Measure the amount of time required for steam to reach the furthest radiator. Then, exit the Max Heat feature and enter the recorded time as the Minimum On Time setting.

Heating Cycle - Heating Curve Section C

Boiler Cycled

On/Off

Boiler On 100% of Heating Cycle

75% 65%

42%

Room @ 70°F

Room @ 55°F

Room @ 75°F

Boiler On 100% of Heating Cycle

0 (°F)102030405060

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

Outdoor reset is a method of operating a heating system based on the fact that the rate at which a building loses heat to the outdoor environment is mostly dependent on the surrounding outdoor air temperature. As the outdoor temperature gets colder, the heat loss of the building increases at a proportional rate. This relationship between heat loss and colder outdoor temperatures is called a heating curve.

Outdoor = 50°F

Outdoor = 30°F

Outdoor = 10°F

A = Indoor Design B = Outdoor Design C = Boiler Design %

Boiler Cycled

On/Off

Outdoor Air Temperature

Percent On Time Per Heating Cycle

Heat Load = 20%

Boiler On Time = 12 min

60 min

Heat Load = 60%

Boiler On Time = 36 min

60 min

Heat Load = 100%

Boiler On Time = 60 min

60 min

In order to calibrate the control to the heat loss rate of a particular building, the installer is required to enter the following heating curve settings:

Indoor Design

The Indoor Design is the starting point of the heating curve. When the measured outdoor air temperature matches the Indoor Design setting, the control calculates a 0% on time is required for heating the building. The factory default is to start the heating curve at 70°F (21°C).

Outdoor Design

The Outdoor Design is the end point of the heating curve. When the measured outdoor air temperature matches the Outdoor Design setting, the control calculates the boiler on time to be at the Boiler Design % setting. The Outdoor Design should be set to the average coldest annual temperature recorded in the building area.

Boiler Design %

The Boiler Design % is the percent output capacity of the boiler or steam system required to heat the building when the measured outdoor air temperature matches the Outdoor Design setting. The factory default is 100%. If the building envelope has been upgraded to improve the building insulation, the existing steam boiler or steam system may be oversized for the building. In these cases, the Boiler Design % can be reduced to fine tune the heating curve.

Room (Occupied and Unoccupied)

The Room setting is the desired temperature of the building. When a setback schedule is selected, there is a Room Occupied temperature setting and a Room Unoccupied temperature setting. When the setback schedule is turned off, only the Room setting is available.

When an indoor sensor(s) is not connected to the control, the Room setting operates as a parallel shift of the heating curve. This allows fine tuning of the heating system. If the Room setting is set above the Indoor Design setting, the entire heating curve is shifted higher, resulting in longer percent on times being calculated. Similarly, if the Room setting is set below the Indoor Design setting, the entire heating curve is shifted lower, resulting in shorter percent on times being calculated.

100%

90%

75% 65%

42%

Room @ 75°F

Room @ 70°F

Room @ 55°F

7080

Outdoor Air Temperature

2030405060

0 (°F)10

80% 70% 60% 50% 40% 30% 20% 10% 0%

Percent On Time Per Heating Cycle

When an indoor sensor(s) is connected to the control, the Room setting becomes a Room Target temperature. The control measures the current air temperature in the room using the indoor sensors. The control then automatically shifts the heating curve so that the measured room temperature reaches the Room Target temperature.

Heating Cycle - Cycle Length Section D

30 minutes

on time

30 minutes

off time

30 minutes

on time

30 minutes

off time

15 minutes

on time

15 minutes

off time

15 minutes

on time

15 minutes

off time

15 minutes

on time

15 minutes

off time

15 minutes

on time

15 minutes

off time

Establishing Steam

(warm-up period)

Lockout Period

Establishing Steam

(warm-up period)

Lockout Period

The Adjust menu includes a setting called Cycle that determines how often the heating system will run. During each heating cycle the boiler is turned on once, and the boiler is turned off once. Each building has a natural heat up and a cool off rate. This is determined by many factors such as the size and length of runs in the steam heating system, the size and mass of the radiators, and the heat loss of the building. The factory default is 60 minutes. When using optional Indoor Sensors, an automatic setting is available that allows the control to learn the natural temperature swing of the building. If the optional Indoor Sensors are not used, then the only method of adjustment is trial and error by the installer.

50% On Time With a 30 Minute Heating Cycle

Off

Boiler

Operation

Boiler On

15 minutes

on time

30 minute cycle

Boiler Off

15 minutes

off time

On Off On Off

15 minutes

on time

30 minute cycle 30 minute cycle 30 minute cycle

15 minutes

off time

50% On Time With a 60 Minute Heating Cycle

Off On

Boiler

Operation

Boiler On

30 minutes

on time

Boiler Off

30 minutes

off time

60 minute cycle

The control is designed to operate on/off steam boilers or steam valves. These systems can only produce heat at a fixed rate (on = 100%, off = 0%). In order to match the heat loss of the building, the steam heating system must be cycled on and off. To determine the boiler on time, the control uses the percent on time required by the heating curve and multiplies this by the heating cycle time. While operating in the heating cycle, the Status field will have a pointer indicating Heat Cycle.

Example:

When the outdoor temperature is 32°F (0°C), the heating curve may determine a 50% on time is required. If the heating cycle is 60 minutes, then the boiler on time is: Boiler On Time Per Heating Cycle = 0.5 x 60 minutes = 30 minutes.

On Off

15 minutes

on time

On Off

15 minutes

off time

30 minutes

on time

15 minutes

60 minute cycle

on time

30 minutes

15 minutes

off time

Lockout Differential Section E

The Adjust menu includes a setting called Lockout Differential. When a condensate return sensor is present, a lockout differential can be set to ensure that any remaining steam in the system condenses and the condensate has time to return to the boiler. This increases the efficiency of the system by removing the latent heat of the steam remaining after the burner is shut down, and lengthening the cycle so that remaining heat is allowed to radiate into the building.

The lockout differential is the number of degrees the condensate return sensor temperature must fall below the steam established setting before the control can operate

Boiler OffBoiler On Boiler Off

Steam established - start cycle

15 minutes

on time

Boiler

Operation

220°F 210°F -

200°F 190°F 180°F 170°F 160°F 150°F 140°F -

Condensate Return Temperature

45 minutes off time 45 minutes off time

60 minute cycle 60 minute cycle

off

30°F Lockout Differential Setting

Steam established

temperature setting

the heating system for the next cycle. During the lockout differential, the heating system is held off, and the Status field will have a pointer indicating Lockout Differential. The factory default is a 25°F lockout differential.

There is no exact method to set the Lockout Differential for a particular building; it is a process of trial and error. If the building tends to over heat, the lockout differential should be increased to allow the steam system to cool down further before starting the next cycle. If the building tends to under heat, the lockout differential should be decreased to allow the next heating cycle to start sooner.

Boiler On

Steam established - start cycle

15 minutes

on time

off

Lockout Period

(warm-up period)

Establishing Steam

Steam Established

on on

Lockout Period

(warm-up period)

Establishing Steam

Optional Indoor Sensors Section F

Multiple indoor sensors can be added to improve the temperature accuracy within the building. Available indoor sensors include the 076, 077 and 084.

Indoor Sensors 084, 077 and 076

The control allows two indoor sensors to be directly connected to the control. Once an indoor sensor is connected to the indoor sensor S1 input, the Indoor S1/Off switch setting must be set to S1. Likewise, once an indoor sensor is connected is connected to the S2 input, the Indoor S2/Off switch setting must be set to S2.

When indoor sensor 1 is present, the Room 1 temperature is visible in the View menu. Likewise, when indoor sensor 2 is present, the Room 2 temperature is visible in the View menu. Also shown in the View menu is the current Room Target temperature. The room target can be changed by adjusting the Room Occupied or Room Unoccupied setting in the Adjust menu.

Should additional indoor sensors be desired, a square number (4, 9, 16, etc.) of sensors can be wired in seriesparallel to a single indoor sensor input.

To Indoor Sensor Input

Series - Parallel

Wiring

When using two indoor sensor inputs, the control can operate either based upon an average of the two temperature measurements or the control can operate on the lowest of the two temperature measurements.

Temperature Averaging

To operate the steam system based upon the average of the two indoor sensor temperature measurements, set the Average/Off switch setting to Average.

Lowest of Two Temperatures

To operate the steam system based upon the lowest of the two indoor sensor temperature measurements, set the Average/Off switch setting to Off.

Built-in Timer Section G

The control includes a built-in time clock that is turned on once the Setback/Off switch setting is set to Setback. The time is set in the Time menu. The clock can be set to use either 12 or 24 hour time.

Programmable Schedule Section H

The control includes a programmable schedule that is turned on once the Setback/Off switch setting is set to Setback. The programmable schedule is set in the Schedule menu. The schedule can be repeated on a 24 hour, 5-1-1, or 7 day schedule. Each schedule allows a time to be set

for the Occupied event and another time to be set for the Unoccupied event. Should it be desired to skip an Occupied or Unoccupied event, set the event time to --:--, which can be found between 11:50 PM (23:50) and 12:00 AM (0:00).

Warm Weather Shut Down Section I

The control includes a Warm Weather Shut Down (WWSD) setting in the Adjust menu. When the Setback/Off switch setting is set to Setback, the control includes WWSD Occupied and WWSD Unoccupied settings.

Once the measured outdoor air temperature exceeds the WWSD setting, the steam system is automatically shut down. Once the measured outdoor air temperature falls below the WWSD, the control is able to start a new heating cycle.

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