tekmar 265 User Manual

- Data Brochure	D 265
Boiler Control 265	07/10

The tekmar Boiler Control 265 can control the supply water temperature on up to three modulating boilers based on outdoor temperature or setpoint requirements. The control can be set to control up to two modulating boilers based on outdoor temperature or domestic hot water requirements. A large easy to read display provides current system temperatures and operating status. The control has outputs for a primary pump, individual boiler pumps, and either a combustion air damper or an alert.

Additional functions include:
•	Outdoor Reset	• DHW demand for domestic hot water loads
• Sequential or Parallel Modulation		• Setpoint demand for setpoint loads
• Installer and Advanced access levels		• 0 – 10 V (dc) BAS / EMS input
•	Primary pump output	• Test sequence to ensure proper component operation
• Individual boiler pump outputs		• Setback input for energy savings
•	Pump purging	• CSA C US certified
• Boiler demand for space heating loads		• Pump exercising

Menu Item

Boiler Control 265

Three Modulating Boiler & DHW / Setpoint

	Do not apply power
Input	1	2	3	4	5
	Com Boil		Boil	Out UnO
Universal	–	Sup	Ret	+	Sw
Sensor
Included

Input

Universal

Sensor

Included

6		7		8		9		10		11
Mod1 mA				Mod2 mA				Mod3 mA
+		–		+		–		+		–

Boiler Demand

DHW / Setpoint Demand

WWSD

Modulation

Boiler Output (x10,000 BTU/hr)

External Input Signal

Offset / Priority Override

Alert		O	Parallel	Rotate
External Input			Soft Stop
Advanced				Fixed Lead
				First On / Last O
Installer	CA.			First On / First O
Stand Alone			O
Exercise
Sequential			Test
				o	not testing
				red	testing
				red	testing paused
				For maximum heat,
				press & hold Test for
				3 seconds.
					Meets Class B:
Made in Canada by					Canadian ICES
tekmar Control Systems Ltd.					FCC Part 15
Power		115 V ±10% 60 Hz 600 VA
Relays		230 V (ac) 5 A 1/3 hp, pilot duty 240 VA
Demands		20 to 260 V (ac) 2 VA			Code
Signal wiring must be rated at least 300 V.					Date

12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

H2037B

Prim

Power

C.A./

Boiler

Boiler

Boiler 3 /

Boiler

Boiler

Boiler

Boil Com Setp/

P1

L

N

Alert

1

1

2

2

DHW

Pump 1

Pump 2

Pump 3

Dem Dem DHW

Input
Outdoor
Sensor
Included
or	or

Input	Input	Output	Output	Output	Output	Input	Output
0-10 V (dc)	Timer or Switch	Modulating	Modulating	Modulating	Primary	115 V (ac)	Combustion Air
External Signal	Optional	Boiler	Boiler	Boiler	Pump	Power Supply	or Alert

Note:

Boiler, DHW, or setpoint demand must

be powered with 20 to 260 V (ac) before the boiler is able to fire.

Input

Setpoint

or DHW

Demand

Input

Boiler

Demand

Output

Pump

Output

Boiler

Enable

or

Pump

Output

Boiler

Enable

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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 seven 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 DIP 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..................................................	Pg 2	Installation.......................................................	Pg 19
Display .............................................................	Pg 3	DIP Switch Settings........................................	Pg 26
Sequence of Operation ..................................	Pg 4	Control Settings..............................................	Pg 28
Section A: General Operation ..............	Pg 4	View Menu ..............................................	Pg 28
Section B: Boiler Operation..................	Pg 6	Adjust Menu ...........................................	Pg 29
Section C: Outdoor Reset.....................	Pg 10	Testing the Control .........................................	Pg 34
Section D: DHW Operation ...................	Pg 13	Error Messages...............................................	Pg 35
Section E: Setpoint Operation .............	Pg 16	Technical Data.................................................	Pg 36
Section F: External Input Operation ....	Pg 17	Limited Warranty ............................................	Pg 36
Section G: Pump Operation..................	Pg 18

User Interface

The 265 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 265 has four push buttons (Menu, Item, ▲, ▼) for selecting 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.

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
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	Menu Item
be viewed within the 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 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 Menu Item and press the ▲ button.

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 Menu Item status field are only visible when the VIEW Menu is selected.

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Display

Menu Field

Displays the current menu

Item Field

Displays an abbreviated name of the selected item

Status Field

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

Number Field

Displays the current value of the selected item

Boiler Demand

DHW / Setpoint Demand

WWSD

Modulation

Boiler Output (x10,000 BTU/hr)

External Input Signal

Offset / Priority Override

Buttons

Selects Menus, Items and adjust settings

Symbol Description

Stage			UnOccupied Schedule
			Displays when the control is in
Displays which boiler relays are turned on.
			UnOccupied Mode.
Primary Pump			Occupied Schedule
Displays when the primary pump relay is
			Displays when the control is in Occupied Mode.
turned on.
Boiler Pump			Installer Access Level
Displays which boiler pump relays are			Displays when the Advanced / Installer Dip switch
turned on.			is set to Installer.
Combustion Air Damper			Pointer
Displays when the Combustion Air Damper			Displays the control operation as indicated by the
relay is turned on.			text.
Delta T			Warning / Alert
The current difference between the supply			Displays when an error exists or the alert relay
and return temperatures.			is turned on.
°F, °C, min, hr			Modulating Output Scale
			Displays the total modulation output level of the
Units of measurement.
			boilers.
DHW
Displays when the DHW relay is turned
on.

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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.

				- Warning Symbol: Indicates presence of hazards which can cause severe personal injury, death or
				substantial property damage if ignored.
				- Double insulated
	INSTALLATION
	CATEGORY II			- Local level, appliances

Sequence of Operation

Section A		Section B		Section C		Section D
General		Boiler		Outdoor		DHW
Operation		Operation		Reset		Operation
Page 4 - 6		Page 6 - 10		Page 10 - 12		Page 13 - 15

Section E		Section F		Section G
Setpoint		External		Pump
Operation		Input Operation		Operation
Page 16		Page 17 - 18		Page 18 - 19

Section A: General Operation

POWERING UP THE CONTROL

When the control is powered up, 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. Finally, the control enters into the normal operating mode.

BOILER TARGET TEMPERATURE

The control operates up to three modulating boilers to control the supply water temperature to a hydronic space heating system or setpoint. When using the control to provide Domestic Hot Water (DHW) requirements, only two modulating boilers can be operated. The supply water temperature is based on boiler reset, an external 0 – 10 V (dc) signal, DHW requirements, or a setpoint temperature.

Boiler Reset (Stand Alone)

When a boiler demand signal from the heating system is present, the control operates the boiler(s) to maintain the supply temperature based on the outdoor air temperature and the Characterized Heating Curve settings. Refer to section C.

DHW

When a DHW demand is present, the control operates the boiler(s) to maintain the supply water temperature at least as hot as the DHW exchange setting. Refer to section D.

		Design Supply
	Terminal Unit	TemperatureWaterIncreasing
	Indoor Design
		Outdoor Design
	Decreasing Outdoor Temperature

Setpoint

When a setpoint demand signal is present, the control operates the boiler(s) to maintain the supply water temperature at least as hot as the Setpoint setting. Refer to section E.

External Input 0 – 10 V (Dc) or 2 – 10 V (Dc)

When an external input signal is present, the control converts the signal to a target supply temperature. The control operates the boiler(s) to maintain the required supply water temperature. Refer to section F.

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SETBACK (OCC and UNOCC)

To provide greater energy savings, the control has a setback feature. With setback, the supply water temperature in the system is reduced when the building is unoccupied. By reducing the supply water temperature, the air temperature in the space may be reduced even when thermostat(s) are not turned down. Any time the UnO Sw (5) and the Com (1) terminals are shorted together, the control operates in the unoccupied mode. When in the unoccupied mode, the UNOCC segment is displayed in the LCD. The control adjusts the supply water temperature based on the UNOCC settings in the control.

1		2		3		4
		Boil		Boil		Out
Com
				Ret		+
		Sup
–

Timer Switch

5

UnO

Sw

COMBUSTION AIR OR ALERT CONTACT

The control has an isolated contact that can be used as either a combustion air damper contact or an alert contact. This selection is made using the C.A. / Alert DIP switch.

Combustion Air (C.A.)

When the DIP switch is set to C.A., terminals 15 and 16 can be used as a switch to operate a combustion air damper. This contact closes prior to the first boiler operating on the control. The amount of time that the contact closes prior to the first boiler firing is set using the combustion delay setting.

The combustion air contact remains closed for a minimum of 15 seconds after the last boiler is turned off.

Alert

When the DIP switch is set to Alert, terminals 15 and 16 can be used as a switch to operate an alert circuit. This contact closes whenever an error message is present on the control display. When the alert contact is activated, refer to the Error Messages section of this brochure to determine the cause of the alert. Once the fault has been fixed, pressing either the Menu, Item, ▲ or ▼ button will clear the alert.

Boiler Alert

The control can monitor the boiler supply temperature and provide an alert if the temperature does not increase within a certain amount of time. The amount of time can be set using the Boiler Alert setting. This alert can be used to determine if the boilers have failed to fire. To reset the alert, press and hold the ▲ and ▼ buttons for 5 seconds while in the VIEW menu.

ROTATION

The control includes an Equal Run Time feature which changes the firing order of the boilers whenever one boiler accumulates 48 hours more running time than any other boiler. After each rotation, the boiler with the least running hours is the first to fire and the boiler with the most running hours is the last to fire. This function ensures that all of the boilers that are being rotated receive equal amounts of use. When the Rotate / Off DIP switch is set to the Off position, the firing sequence always begins with lowest boiler to the highest boiler.

Fixed Lead Rotation

In some applications, it may be desirable to have the first boiler fire first at all times while the firing sequence of the remaining boilers is changed using Equal Run Time Rotation. This rotation option is selected by setting the Fixed Lead / Off DIP switch to the Fixed Lead position.

First On / Last Off or First On / First Off

1	2
720 hours	672 hours
2	1
672 hours	720 hours

When using the Fixed Lead rotation option, a selection must be made between First On / Last Off and First On / First Off using the DIP switch. When First On / Last Off is selected, the lead boiler is always modulated first and shut off last. When First On / First Off is selected, the lead boiler is always modulated first and shut off first. This DIP switch is only read by the control when the Fixed Lead / Off DIP switch is set to Fixed Lead.

Resetting the Rotation Sequence

To reset the rotation sequence, set the Rotate / Off DIP switch to the Off setting for 5 seconds and then return the DIP switch to the Rotate setting.

RUNNING TIMES

The control displays the accumulated running time of each boiler in the VIEW menu.

Resetting the Running Times

To reset the running time for each boiler, select the appropriate running time in the VIEW menu. Next press the ▲ and ▼ buttons simultaneously until CLr is displayed.

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EXERCISING

The control has a built-in exercising feature that is selected through the Exercise / Off DIP switch. To enable the exercising feature set the Exercise / Off DIP switch to Exercise. If exercising is enabled, the control ensures that each pump is operated at least once every 3 days. If a pump has not been operated at least once every 3 days, the control turns on the output for 10 seconds. This minimizes the possibility of the pump seizing during a long period of inactivity. While the control is exercising, the Test LED flashes quickly.

Note: The exercising function does not work if power to the control or pumps is disconnected.

FACTORY DEFAULTS

The control comes preset with several factory defaults. These defaults are based on the terminal unit selection (see section C). To fine-tune building requirements, these defaults may be changed.

To reload the factory defaults listed in the ADJUST Menu, power down the control and wait for 10 seconds. Power up the control while simultaneously holding the Menu and ▼ buttons. An E01 error occurs forcing the installer to go through the ADJUST menu to ensure the settings are correct.

Section B: Boiler Operation

Section B1

Boiler

Modulation

Section B1: Boiler Modulation

MODULATION

The control provides three modulating output signals, three boiler enable contacts, and three boiler pumps contacts to operate up to three modulating boilers. The boiler enable contact may not be required, depending on the make and model of the boiler(s).

The control operates a boiler by first closing the boiler pump contact. The boiler enable contact is closed next and then the control provides a modulating output signal to the boiler.

The modulation output signal is then modulated from the minimum modulation using Proportional, Integral and Derivative (PID) logic in order to satisfy the boiler target temperature.

SEQUENTIAL MODULATION

The control offers a sequential modulation option. This is selected by setting the Sequential / Parallel DIP switch to Sequential. Sequential modulation should be used on boilers that are more efficient when operating at high fire.

In sequential modulation, the first boiler is turned on and is modulated to satisfy light loads. Once the first boiler does not have enough capacity to satisfy the load, the first boiler reduces its modulation to provide a smooth transition when the second boiler fires at low fire. The first boiler then modulates up to maximum modulation as the load increases. Only then is the second boiler able to increase its output as the load continues to increase. When the third boiler is required, the second boiler reduces its modulation to allow the third boiler to operate at low fire. As the load continues to increase, the second boiler is modulated to its maximum and then the third boiler is modulated. The operation is reversed when shutting off the boilers.

PARALLEL MODULATION

The control offers a parallel modulation option. This is selected by setting the Sequential / Parallel DIP switch to Parallel. Parallel modulation should be used on boilers that are more efficient when operating at low fire.

In parallel modulation, the first boiler turns on at low fire and begins to increase its modulation. Once the first boiler’s output is greater than the combined output of the first and second boiler’s low fire, the first boiler is modulated down to low fire and the second boiler is fired at low fire. The two boilers now modulate together. Once the two boiler’s combined output is greater than the combined output of all three boilers operating at low fire, the first and second boilers are modulated down to low fire, and all three boilers are operated at low fire. The boilers are then modulated as the load increases. The operation is reversed when shutting off the boilers.

	SEQUENTIAL MODULATION
100%			MOD			OFF

Boiler 1

Boiler 2

Boiler 3

	PARALLEL MODULATION
MOD	MOD	MOD

Boiler 1		Boiler 2		Boiler 3

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MODULATION RANGE (4 to 20 mA or 0 to 20 mA)

The modulation output (Mod 1, Mod 2, and Mod 3) for each boiler can be adjusted from a 4 to 20 mA output range to a 0 to 20 mA output range using the Boil Modulation 1, Boil Modulation 2, or Boil Modulation 3 setting. The resulting modulation output signal can be converted to a 0 to 5 V (dc), 1 to 5 V (dc), 0 to 10 V (dc), and 2 to 10 V (dc) output using external resistors. The modulation output signal can be converted to a 0 to 135 Ω (W R B) output using a 0 - 135 Ω Converter 005. Refer to the Modulation Output section in Step 4 of the Installation section.

MINIMUM MODULATION

The minimum modulation defines the minimum output signal from the control to the boiler burner. It is based on a percentage of the control’s output signal range.

The minimum modulation setting for boilers with power burners is typically set to 0%.

For boilers with electronic operators, the boiler’s input signal range may not match the output signal range of the 265 control. The Minimum Modulation setting limits the control output range in order to match the boiler’s input range.

To calculate the Minimum Modulation, use the following formulae:

MINIMUM MODULATION

For 4 to 20 mA:

Minimum Modulation = 4 mA – Boiler’s Minimum Input Signal x 100% 4 - 20 mA

For 0 to 10 V (dc):

Minimum Modulation = 0 V (dc) – Boiler’s Minimum Input Signal x 100% 0 – 10 V (dc)

For 2 to 10 V (dc):

Minimum Modulation = 2 V (dc) – Boiler’s Minimum Input Signal x 100% 2 – 10 V (dc)

Example 1:

10 V (dc)

100%

10 V (dc)

Control's

Boiler's

Output

Input

Signal

Signal

Range

Range

18%

1.8 V (dc)

0 V (dc)

0%

Minimum

Boiler's Minimum

Modulation

Input Signal

A boiler requires a 1.8 V (dc) signal to fire the boiler at low fire. The boiler can be modulated to 10 V (dc) where it reaches high fire. This means the boiler’s input signal range is 1.8 to 10 V (dc). The 265 control has an output signal range of 0 to 20 mA which can be externally converted to 0 to 10 V (dc) using a 500 Ω resistor (Refer to Modulation Output section in Step 4 of the Installation section).

To make the two signal ranges the same, the Minimum Modulation required is:

Minimum Modulation = 0 V – 1.8 V x 100% = 18% 0 V – 10 V

Example 2:

If the boiler’s input signal range is 6 to 20 mA the required Minimum Modulation is:

Minimum Modulation = 4 mA – 6 mA x 100% = 13% 4 mA – 20 mA

MAXIMUM MODULATION

The maximum modulation defines the maximum output signal from the control to the boiler burner. It is based on a percentage of the control’s output signal range.

The maximum modulation setting for boilers with power burners is typically set to 100%.

For boilers with electronic operators, the boiler’s input signal range may not match the output signal range of the 265 control. The Maximum Modulation setting limits the control output range in order to match the boiler’s input range.

To calculate the Maximum Modulation, use the following formulae:

For 4 to 20 mA:

Maximum Modulation = 4 mA – Boiler’s Maximum Input Signal x 100% 4 – 20 mA

For 0 to 10 V (dc):

Maximum Modulation = 0 V (dc) – Boiler’s Maximum Input Signal x 100% 0 – 10 V (dc)

For 2 to 10 V (dc):

Maximum Modulation = 2 V (dc) – Boiler’s Maximum Input Signal x 100% 2 – 10 V (dc)

MAXIMUM MODULATION
10 V (dc)						100%
					88%				9 V (dc)
Control's										Boiler's
Output										Input
Signal										Signal	Boiler's
Maximum Range										Range
Modulation											Maximum
											Input Signal

2 V (dc)

0%

2 V (dc)

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Example 1:

A boiler’s input signal range is 2 to 9 V (dc). The 265 control has an output signal range of 2 to 10 V (dc). To make the two signal ranges the same, the Maximum Modulation required is:

Maximum Modulation = 2 V – 9 V x 100% = 88% 2 V – 10 V

Example 2:

If the boiler’s input signal range is 6 to 19 mA the required Maximum Modulation is:

Maximum Modulation = 4 mA – 19 mA x 100% = 94% 4 mA – 20 mA

MINIMUM BOILER OUTPUT

In order to accommodate different boiler capacities in the same system, a minimum boiler output for each boiler can be set. This allows the control to properly operate the boilers using either sequential or parallel modulation. The minimum boiler output range is from 10,000 BTU / hour to 19,990,000 BTU / hour.

Each boiler typically has a rating plate that specifies the minimum output. This information is also available in the boiler manual. The Minimum Boiler Output setting has units of 10,000 BTU / hour. Divide the minimum output rating by 10,000 and enter the number as the Minimum Boiler Output setting.

For example, if a boiler has a minimum output of 20 MBH:

Minimum Boiler Output = 20,000 BTU/hr = 2 x 10,000 BTU/hr 10,000

MAXIMUM BOILER OUTPUT

In order to accommodate different boiler capacities in the same system, there is a maximum boiler output for each boiler. This allows the control to properly operate the boilers using either sequential or parallel modulation. The maximum boiler output range is from 10,000 BTU / hour to 19,990,000 BTU / hour.

Each boiler typically has a rating plate that specifies the maximum output. This information is also available in the boiler manual. The Maximum Boiler Output setting has units of 10,000 BTU / hour. Divide the maximum output rating by 10,000 and enter the number into the Maximum Boiler Output setting.

For example, if a boiler has a maximum output of 100 MBH:

Maximum Boiler Output = 100,000 BTU/hr = 10 x 10,000 BTU/hr 10,000

MOTOR SPEED

The Motor Speed is the amount of time the boiler requires to go from 0% modulation to 100% modulation. The control includes a Motor Speed setting for each individual boiler.

Gas valve actuating motors have a design time from fully closed to fully opened which can be found in the manufacturer’s manual. The Motor Speed should be set to this time.

The Motor Speed setting for a Variable Frequency Drive (VFD) is the amount of time required to go from a stopped position to 100% fan speed. Since a VFD has a very quick response rate, it may be necessary to increase the Motor Speed setting in order to increase the stability of the boiler modulation.

BOILER MASS

The boiler mass setting allows the installer to adjust the control to the thermal mass of the type of heat sources used in the application. There is a boiler mass setting for each boiler. The modulation of the boiler can become unstable if the incorrect Boiler Mass setting is chosen. A key sign of the boiler modulation being unstable is the flame will continue to increase and then decrease in short periods of time. By choosing a lower boiler mass setting, the boiler response will become more stable.

Lo (1)

The Lo setting is selected if the boiler that is used has a low thermal mass. This means that the boiler 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 Lo mass setting provides a fast response to the heating system.

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Med (2)

The Med setting is selected if the boiler that is used has a medium thermal mass. This means that the boiler 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 Med mass setting provides a moderate response to the heating system.

Hi (3)

The Hi setting is selected if the boiler that is used has a high thermal mass. This means that the boiler 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 Hi mass setting provides a slow response to the heating system.

DIFFERENTIAL

A modulating boiler must be operated with a differential while operating in low fire. The boiler differential is divided around the boiler target temperature. The boiler starts at low fire when the supply water temperature is ½ of the differential setting below the boiler target temperature. The boiler is shut off in low fire as the supply temperature reaches at least ½ of the differential above the boiler target temperature. With the control, either a fixed or an auto differential may be selected.

When the boiler is modulating above low fire, the differential does not apply. Instead, the modulation output signal is determined using Proportional, Integral and Derivative (PID) logic in order to satisfy the boiler target temperature.

Fixed Differential

If the user desires to have a fixed differential, this is set using the boiler differential setting in the ADJUST menu.

Desired temperature 160°F (71°C)

Boiler O

165°F (74°C)

			p	e	r	a
		m
	e
T
Boiler On

Di erential

10°F (6°C)

						e	T
					i s		e
							p
				r			m
		r	e				e
							a
							t
t	u						r
							u
							r
							e
							f
							a
							l
							l

155°F (68°C)

Auto Differential

If the Auto Differential is selected, the control automatically determines the best differential as the load changes. This reduces potential short cycling during light load conditions.

BOILER MINIMUM

The boiler minimum is the lowest temperature that the control is allowed to use as a boiler target temperature. During mild conditions, if the control calculates a boiler target temperature that is below the boiler minimum setting, the boiler target temperature is adjusted to at least the boiler minimum setting. During this condition, if the boiler(s) is operating, the minimum segment is turned on in the display when viewing either the boiler supply temperature or the boiler target temperature. Set the boiler minimum setting to the boiler manufacturer’s recommended temperature.

BOILER MAXIMUM

The boiler maximum is the highest temperature that the control is allowed to use as a boiler target temperature. If the control does target the boiler maximum setting, and the boiler temperature is near the boiler maximum temperature, the maximum segment will be turned on in the display while either the boiler target temperature or the boiler supply temperature is being viewed. At no time does the control operate the boiler(s) above 248°F (120°C).

Time

O

	Di erential	On	Load
			Increasing
	Time

MIN Segment On

MAX Segment

MAX Segment

On

On

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FIRE DELAY

The Fire Delay is the time delay that occurs between the time that the control closes a boiler enable contact to fire a boiler and when the boiler fires at low fire.

STAGE DELAY

The stage delay is the minimum time delay between the firing of stages. After this delay has expired the control can fire the next stage if it is required. This setting can be adjusted manually or set to an automatic setting. When the automatic setting is used, the control determines the best stage delay based on the operation of the system.

SOFT STOP

Boiler 1

Boiler 2

Boiler 3

Contact Closes

Contact Closes

Contact Closes

Boiler 1

Boiler 2

Boiler 3

Fires

Fires

Fires

Stage Delay

Stage Delay

Fire

Fire

Fire

Delay 1

Delay 2

Delay 3

Time

It is possible to thermally shock a boiler when it is shut off at high fire. The Soft Stop feature forces the boiler to modulate down to minimum before turning off. This is designed to prevent large volumes of cold air being introduced into the combustion chamber of the boiler when it is shut off. This can occur in applications where the burner includes a fan.

Once all demands are removed, the control allows for the firing rate to be modulated down to the MIN Modulation setting prior to turning off the burner. This feature is enabled by setting the Soft Stop / Off DIP switch to the Soft Stop position. If the Soft Stop / Off DIP switch is in the Off position, the control turns off the boiler at the current firing rate once all demands are removed.

COPY BOILER 1 SETTINGS

Many boiler installations will have multiple identical boilers. To reduce the number of settings required, the settings of boiler 1 (Fire Delay, Boiler Mass, Motor Speed, Minimum Boiler Output, Maximum Boiler Output, Boiler Modulation, Minimum Modulation, Maximum Modulation, and Purge Boiler Pump) are copied to boiler 2 by setting the Boiler 2 setting to CP1. Likewise, setting Boiler 3 to CP1 copies the settings of boiler 1 to boiler 3. Boiler 2 and Boiler 3 settings are set to CP1 by default.

The setting of CP1 allows the control to enable the boiler similar to the setting of Au (automatic). If a boiler is set to OFF, the control disables that boiler.

If required, each of the three modulating boilers can have individual boiler settings. This allows for three different type, size, and make of modulating boilers. To select individual boiler settings for boiler 2, set Boiler 2 to Au (automatic). Likewise, to select individual boiler settings for boiler 3, set Boiler 3 to Au (automatic).

Section C: Outdoor Reset

Section C1

Boiler Reset

(Stand Alone)

Section C1: Boiler Reset (Stand Alone)

Boiler Reset operation only applies when the Stand Alone / External Input DIP switch is set to

Stand Alone.

BOILER DEMAND

A boiler demand is required in order for the control to provide heat to the heating system. A boiler
demand is generated by applying a voltage between 24 and 230 V (ac) across the Boil Dem	24 to 230 V (ac)
and Com Dem terminals (29 and 30). Once voltage is applied, the Boiler Demand pointer is
displayed in the LCD. If the control is not in Warm Weather Shut Down (WWSD), the control
closes the primary pump contact. The control calculates a boiler target supply temperature
based on the outdoor air temperature and the characterized heating curve settings. The control
then fires the boiler(s), if required, to maintain the target supply temperature.

29	30
Boil	Com
Dem	Dem

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CHARACTERIZED HEATING CURVE

The control 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, natural convection and forced convection, the supply water temperature must be controlled differently. Once a terminal unit is selected, 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.

OUTDOOR DESIGN TEMPERATURE

The outdoor design temperature 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.

						210
						(99)
Boiler Characterized				BOIL DSGN	BOIL MAX
	Heating Curve					190
						(88)
						170	Temperature
						(77)
	BOIL MIN					150
						(66)
						130
							Water
						(54)
				OUT DSGN		110
							Supply
						(43)
			WWSD OCC			90
BOIL INDR			WWSD UNOCC
						(32)
			ROOM OCC			70
						(21)
			ROOM UNOCC			50°F
80	60	40		20	0	(10°C)
						-20
(27)	(16)	(5)		(-7)	(-18)	(-29)

BOILER DESIGN TEMPERATURE

Outdoor Air Temperature

The boiler design supply temperature is the supply water temperature required to heat the building when the outdoor air temperature is as cold as the outdoor design temperature.

BOILER INDOOR DESIGN TEMPERATURE

The indoor design temperature is the room temperature that was used in the original heat loss calculations for the building. This setting establishes the beginning of the characterized heating curve.

ROOM

The ROOM setting is the desired room temperature for the building and provides a parallel shift of the heating curve. The room temperature desired by the occupants is often different from the design indoor temperature. 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) periods.

BOILER TARGET TEMPERATURE

The boiler 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.

TERMINAL UNITS

The control provides for a selection between six different terminal unit types: two types of radiant floor heat, fancoil, fin-tube convector, radiator and baseboard. When a terminal unit is selected, the control automatically loads the design supply temperature, maximum supply temperature, and minimum supply temperature. The factory defaults are listed below. These factory defaults can be changed to better match the installed system.

Terminal Unit	High Mass	Low Mass	Fancoil	Fin-Tube	Radiator	Baseboard
	Radiant (1)	Radiant (2)	(3)	Convector (4)	(5)	(6)
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 MAX	140°F (60°C)	160°F (71°C)	210°F (99°C)	200°F (93°C)	180°F (82°C)	170°F (77°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 floor is embedded in either a thick concrete or gypsum pour. This heating system has a large thermal mass and is slow acting.

Low Mass Radiant (2)

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 sub-floor and the surface. This type of radiant system has a relatively low thermal mass and responds faster than a high mass system.

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© 2010

D 265 - 07/10