tekmar 279 User Manual

- Data Brochure	D279
Steam Control 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

• DHW Tankless Coil Operation

• Outdoor Reset

• Warm Weather Shut Down

• Manual Override

• Built-in Programmable Timer

• Includes Outdoor Sensor

• 24 Hour, 5-1-1, 7 Day Schedule

• Includes Condensate Sensor

• Two or Four Schedule Events Per Day

• Large LCD Display

• Two Alert Level Relays

• Optional Indoor Sensors

Average

Condensate Sensor

Indoor S2

DHW Tankless Coil Sensor

STATUS

Indoor S1

Setback

Installer

Establishing Steam

User

Heat Cycle

O

Lockout Differential

Test

DHW Tankless Coil Heating

o

not testing

red

testing

red

testing paused

For manual operation,

press and hold Test

button for 3 seconds.

Menu Item

Made in Canada By

Meets Class B:

Canadian ICES

tekmar Control Systems Ltd.

FCC Part 15

tektra 969-04

Steam Control 279

Power

115 V ±10% 50/60 Hz 3.5 VA

Code

Relays

230 V (ac) 5 A 1/3 hp, pilot duty 240 VA

One Stage

Signal wiring must be rated at least 300 V.

Date

Do not apply power

1

2

3

4

5

6

7

8

9

10

11 12 13

14 15 16

H2046A

Power

Alert 1

Alert 2

Boiler

Com Com DHW Indr

Indr

Com Cdn

Out

L

N

High

Low

Sen

Sen

Sen S2

S1

Sen Sen

Sen

Input					Input
115 V (ac)					Outdoor
Power Supply					Sensor
					Included
Output					Input
High Priority					Universal Sensor
Alert					Included
	OR	M
Output	Output	Input	Input	Input
Low Priority	Boiler or On /Off	Universal Sensor	Indoor Sensor	Indoor Sensor
Alert	Steam Valve	Optional	Optional	Optional
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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.

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.

Table of Contents

User Interface ...............................................................	2	Alert Relay Operation ...........................................	9
Display and Symbol Description ...................................	3	Domestic Hot Water Tankless Coil .....................	10
Definitions.....................................................................	4	Installation ..................................................................	10
Sequence of Operation.................................................	4	Cleaning the Control...................................................	14
General .................................................................	4	Switch Settings ...........................................................	15
Establishing Steam ...............................................	4	Display Menus ............................................................	16
Heating Cycle .......................................................	6	View Menu ..........................................................	16
Lockout Differential ...............................................	7	Adjust Menu........................................................	17
Optional Indoor Sensors.......................................	8	Time Menu..........................................................	19
Built-in Timer ........................................................	8	Schedule Menu...................................................	20
Programmable Schedule ......................................	8	Testing the Control......................................................	20
Warm Weather Shut Down ...................................	8	Troubleshooting ..........................................................	21
Optimum Start ......................................................	9	Error Messages ..........................................................	22
Boost ....................................................................	9	Technical Data ............................................................	24
Limited Occupied ..................................................	9	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.

Menu

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 thebutton. To rapidly scroll through the items in the reverse order, hold the Item button and press thebutton.

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.

© 2010	D 279 - 05/10	Menu Item
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Display

Number Field

Status Field

Menu Field

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

	Displays the	STATUS
	current menu
		Establishing Steam
		Heat Cycle
	Item Field	Lockout Differential
	Displays the current	DHW Tankless Coil Heating
	item selected.

Buttons

Selects Menus, Items

and adjusts settings

Menu Item

Symbol Description

	POINTER			USER ACCESS LEVEL
				Displays when the Installer / User
	Displays the control operation as
				Switch Setting is set to the User
	indicated by the text.
				access level.
	°F, °C			STEAM ESTABLISHED
°F°C				Displays once the condensate sensor
	Units of measurement.			reaches a temperature sufficient for
				steam to reach the furthest radiator.
	OCCUPIED SCHEDULE			BOOST
				Displays while the boost feature
	Displays when the control is in the
				extends the boiler on time to allow
	Occupied event period.
				recovery after night setback.
	UNOCCUPIED SCHEDULE			OPTIMUM START
				Displays while the Optimum Start
	Displays when the control is in the
				feature extends the boiler on time to
	Unoccupied event period.
				allow recovery after night setback.
	BURNER			WWSD
	Displays when the boiler contact is			Displays while the control is in Warm
	turned on.			Weather Shut Down.
	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.

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Definitions

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		Status
When the control is powered on, all segments in the LCD		The control has a status field on the right hand side of the
are turned on for 2 seconds. Next, the control displays the		control. A pointer is shown in the status field once the boiler
control type number in the LCD for 2 seconds. Next, the		contact is turned on. The pointer indicates at which point
software version is displayed for 2 seconds. Last, the control		of the steam heating system cycle the control is currently
enters into the normal operating mode.		operating at.
Boiler Contact Operation		The steps are as follows:
		• Establishing Steam
In single on-off steam boiler applications, the control uses
		• Heat Cycle
the boiler contact to connect to the thermostat terminals
		• Lockout Differential
(T-T) on the boiler. The pressure control and all other safety
		• DHW Tankless Coil Heating
devices and circuits must continue to be wired in series to
the burner circuit. The boiler contact on the control is used											STATUS
to turn on or off the steam boiler burner.											Establishing Steam
											Heat Cycle
In steam valve applications, the boiler contact on the control
					STATUS						Lockout Differential
is used to power the valve motor to open the valve. When											DHW Tankless Coil Heating
power is removed, the valve must close.					Establishing Steam
		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.

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The Adjust menu includes a Steam Established setting that 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

Radiator

Vent

Main
Air Vent	Best
	Supply Main
OK	Condensate Return
	Sensor Location

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:

	Thermostatic
	Trap
	Best
	Supply
	Air Vent
Return	Float &
Air Vent
	Thermostatic
	Trap
	OK
	Condensate Return
	Sensor Location

			Boiler On		Boiler Off		Boiler On	Boiler Off
Boiler					Steam established - start cycle			Steam established - start cycle
	Off			15 minutes	45 minutes off time		15 minutes	45 minutes off time
				on time			on time
					60 minute cycle			60 minute cycle
Condensate Return TemperatureOperation		EstablishingSteam	(warm-upperiod)			EstablishingSteam
	220°F -
	210°F -				off			off
	200°F -
	190°F -
	180°F -
	170°F -			est.			est.
	160°F -			Steam established			period)(warmup-
	150°F -			temperature setting		on
	140°F -
		on
				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.

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Heating Cycle - Heating Curve

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

Heat Load = 20%

Outdoor = 30°F

Heat Load = 60%

Outdoor = 10°F

Heat Load = 100%

Boiler On Time = 12 min

Boiler On Time = 36 min

Boiler On Time = 60 min

60 min

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.

Section C

																		- 100%	HeatingPer Cycle
		A = Indoor Design												C		Heatingof Cycle
																		- 50%
		B = Outdoor Design																- 90%
		C = Boiler Design %																- 80%
																		- 70%
																		- 60%
										Boiler Cycled						100%		- 40%	Time
																On		- 30%	On
										On/Off
																		- 20%
																Boiler			Percent
																		- 0%
		A												B				- 10%
80		70		60		50		40		30		20		10			0 (°F)
						Outdoor Air Temperature

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%	Cycle
													- 90%
													- 80%
											75%			Heating
													- 70%
											65%
						75°F							- 60%
														Per
											42%		- 50%
				@			70°F
		Room			@				55°F				- 40%	Time
													- 30%
			Room					@						On
				Room									- 20%
														Percent
													- 10%
80	70	60	50					40		30	20		- 0%
												10	0 (°F)

Outdoor Air Temperature

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.

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Heating Cycle - Cycle Length

Section D

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.

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.

Boiler	Operation
Boiler	Operation

50% On Time With a 30 Minute Heating Cycle

Off

Boiler On

Boiler Off

On

Off

On

Off

On

Off

On

15 minutes

15 minutes

15 minutes

15 minutes

15 minutes

15 minutes

15 minutes

15 minutes

on time

off time

on time

off time

on time

off time

on time

off time

30 minute cycle

30 minute cycle

30 minute cycle

30 minute cycle

50% On Time With a 60 Minute Heating Cycle

Off	Boiler On		Boiler Off	On			Off			On
	30 minutes		30 minutes			30 minutes			30 minutes
	on time		off time			on time			off time

60 minute cycle 60 minute cycle

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

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		Boiler Off		Boiler On			Boiler Off
Boiler Operation		Steam established - start cycle					Steam established - start cycle
	15 minutes	45 minutes off time				15 minutes
	on time			Establishing Steam		on time	45 minutes off time		Establishing Steam
		60 minute cycle	Lockout Period		(warm-up period)		60 minute cycle	Lockout Period		(warm-up period)
220°F -
210°F -		off					off
200°F -
		Steam established
190°F -		temperature setting
180°F - Condensate
170°F -	Return Temperature
						Steam Established
160°F -		30°F Lockout
150°F -		Differential Setting
140°F -				on					on
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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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