tekmar 269 User Manual

- Data Brochure

D 269

One Stage Steam Control 269

The tekmar One Stage Steam Control 269 is a microprocessor-based control which regulates the firing time of a steam boiler based on user settings, outdoor air temperature, condensate return temperature, and optionally, the indoor air temperature(s). The steam boiler can be operated in the outdoor reset mode, or in Manual Override mode based on dial settings. The control has builtin diagnostics for sensor checking with a Warning output for error reporting. Other control operation features include Auxiliary relay output, Steam Established and Lockout Differential temperatures, and Early Start with setback limit when using the Unoccupied input.

70°F

(21°C)

100

(4)

(38)

Occupied

Unoccupied

One Stage Steam Control 259

with Early Start

Steam

Power

established

Heating

WWSD

cycle

Early Start

UnOcc.

Auxiliary

Warning

100 (38)

Boiler

LR 58233

E150539

Outdoor Reset Strategy . . pg. 2 Sequence of Operation . . . pg. 3

Installation . . . . . . . . . . . . . pg. 6

Settings . . . . . . . . . . . . . . . pg. 8

Early Start

into or

out of UnOcc.

System is in

Warm Weather

Shut Down

System is in Unoccupied

mode

Sensor Fault

warning

Occupied

temperature

setting

Unoccupied temperature

setting

Boiler is on

120Vac power

supply is on

70°F

(21°C)

100

(4)

(38)

Occupied

One Stage Steam Control 269

with Early Start

Use Nº 20 AWG or larger copper conductors rated for at least 75°C and 300V.

Heating Cycle

is in progress

70°F

(21°C)

100

(4)

(38)

Unoccupied

1234 5

Power

Warn.

Aux.

Condensate

temperature is

established

Power

WWSD

UnOcc.

Warning

LR 58223

Boiler

Auxiliary relay

output is on

Steam Established

Heating Cycle

Early Start

Auxiliary

Boiler

Listed

5T62

E150539

Testing . . . . . . . . . . pg. 9

Error Messages . . . pg. 11

Technical Data . . . . pg. 12

Limited Warranty . . pg. 12

Operating Mode

selector switches

Indoor Sensor S1 Indoor Sensor S2

Early Start

45%

Auto

100

Man. Override

Test

Manufactured

in Canada by

Power: 120V 50/60Hz 3VA Relays: 120Vac 10A 1/4 hp 240VA, 2A pilot duty Enclosed Energy Management Equipment

10K

Condensate Return Sensor

123 4

Off

0 °F

180 °F

Steam

11 12

UnO

Cycle Length

Off2550

Min. On Time (%) Lockout Diff'l (°F)

13 14 15

Com

10K

Sen

2093 1234567

Cnd Out Sen

-40

Design Out

130 230

Established

Do not apply power here

Com Sen

50 min

06/00

Manual override setting

System design outdoor temperature setting

Heating cycle length setting

Steam established

100

(condensate temperature) setting

Minimum on time/lockout differential

Date

S/N

setting

Test button and LED to test main control functions

H1099

Sen

Terminal Plugs:

Power and out-

put connections

120 Vac

power supply

Warning Relay

Output:

Auxiliary Relay

Output:

Turn on boiler

Input: Indoor

Sensor 074

Optional

Input: Unoccupied signal

Optional

Input: Outdoor Sensor 070. Included

Input: Condensate Return Sensor 071. Included

Input: Indoor

Sensor 074

Optional

Outdoor Reset Strategy

Boiler off

15 minutes

off time

15 minutes

off

on time

Boiler Operation

Boiler on

30 minute cycle

Figure 1. 50% on time with a 30 minute heating cycle

Boiler on

off

Boiler Operation

30 minutes

on time

60 minute cycle

Figure 2. 50% on time with a 60 minute heating cycle

Boiler is turned off

WWSD

Point

(32)

(21)

Boiler is cycled on/off

Design

Outdoor

Temperature

(10)

Outdoor air temperature

(-1)10(-12)

-10°F

(-23)°C

Figure 3. Outdoor Reset of boiler % on time

15 minutes

on time

30 minute cycle 30 minute cycle 30 minute cycle

off

15 minutes

off time

15 minutes

on time

off

15 minutes

off time

15 minutes

on time

Boiler off

30 minutes

off time

30 minutes

on time

off

30 minutes

60 minute cycle

100%

90%

80%

70%

60%

50%

40%

30%

Boiler is turned on 100%

20%

10%

0% on time

-30°F

(-34)°C

Most residential and small commercial steam systems can only produce heat at a fixed rate and are either on (100% output), or off (0% output). When 100% output is not required (warmer weather), the boiler must be cycled on and off in order to prevent overheating. Figures 1 and 2 illustrate the operation of two heating systems with different heating cycle times.

Cycle times are selected based on the operating characteristics of each individual heating system. Figure 1 shows a system where a 30 minute cycle is required, and Figure 2 shows a system where a 60 minute cycle is required. In both examples the heating plant output is exactly the same at 50%.

As the outdoor temperature changes, the % on time of the boiler should be changed to match the changing heat losses of the building. Figure 3 illustrates how Outdoor Reset of a steam boiler changes the % on time from

Percentage of boiler on time per cycle

0% at the Warm Weather Shut Down point, to 100% at design outdoor conditions (coldest day of the year). Applying this chart to the system represented in Figure 1, we see that the outdoor temperature would be at 30°F with the 50% on time that is illustrated, and if the outdoor temperature warmed up to 50°F, the system would operate with a 25% on time as illustrated in Figure 4. Using outdoor temperature to reset the % on time in this manner can help minimize the overheating and wide temperature swings found in many systems that use only room temperature control.

off time

off

15 minutes

off time

Boiler off

45 minutes off time

60 minute cycle

15 minutes

on time

off

45 minutes off time

60 minute cycle

15 minutes

off

on time

Boiler Operation

Boiler on

Figure 4. 25% on time with a 60 minute cycle time

Before adding this control to a steam system, it is very important that the installer examine the

complete

system and how it works. In order to properly install and setup this control, the installer must know: the optimum cycle length and minimum on time of the system, the outdoor temperature at which 100% boiler on time will be required, and the best locations to install sensors. In addition to examining the boiler operation,

all other

system components such as steam traps, air vents, radiators, piping, etc. should be examined for correct operation to ensure that the system is working at its peak efficiency. If there are existing faults that degrade the operation of the system, it is quite likely that the addition of this control could allow those faults to have an even greater effect, making it important to correct such faults or at least point them out to the end user.

Sequence of Operation

Start-up

When the One Stage Steam Control 269 is powered-up, the "Power" light and all of the red lights will come on. After 5 seconds the red lights will go out and the control will enter the operating mode. If there is a sensor error detected, the control will display an error message (see "Error Messages", page 11).

Power

WWSD

UnOcc.

Warning

Manual Override function

If the "Man. Override" dial is turned up from the "Auto" position, the WWSD, Heating Cycle, Early Start and UnOcc. lights will cycle on and off in a clockwise, circular sequence and the control will continually operate the system at the % on time setting of the "Man. Override" dial position.

Power

WWSD

UnOcc.

In this mode, the only two dial adjustments that will have any influence on the control's operation will be the "Man. Override" and the "Cycle Length" dials, and the control will cycle the boiler on

Warning

and off as illustrated in Figures 1, 2 and 4 on page 2. Outdoor or room temperatures will have no effect on the operation of the control when it is in "Man. Override" mode.

Auto (reset) function

If the "Man. Override" dial is set to the "Auto" (Outdoor Reset) operating mode, the control uses the Outdoor Sensor 070 to continually monitor the outdoor temperature. As options, a Condensate Return Sensor 071 can continually monitor the temperature of the condensate return line and one or two Indoor Sensors 074 can continually monitor the indoor air temperature. DIP switches for Condensate Return Sensor and Indoor sensors must be switched on when these sensors are connected.

An Error Message

will be displayed if these switches are in the on position without sensors installed.

While monitoring all of these temperatures, the control recognizes the following inputs and will respond as described. During operation, the lights of the control will indicate operational status as illustrated.

Outdoor Sensor 070 only

When an Outdoor Sensor 070 is connected to the control and the "Design Out" dial set to the correct setting, the control will cycle the boiler on and off based on the outdoor temperature and the settings on the "Cycle Length" and "Min. On Time (%)" dials as shown in Figure 5.

The "Min. on time (%)" dial must be set to at least the minimum time required for the boiler to produce steam and add heat to the building.

As soon as the outdoor temperature drops below the setting of the "Occupied" dial (WWSD point), the "WWSD" light will go out and the "Heating Cycle" and "Auxiliary" lights will come on. The "Boiler" light will come on and the

123 4

Off

Power

WWSD

UnOcc.

Warning

Indoor Sensor S1 Indoor Sensor S2

Condensate Return Sensor

Steam established

Heating cycle

Early Start

Auxiliary

Boiler

123 4

Off

Power

WWSD

UnOcc.

Warning

Indoor Sensor S1 Indoor Sensor S2

Condensate Return Sensor

Steam established

Heating cycle

Early Start

Auxiliary

Boiler

Condensate return sensor,

+ Indoor sensors S1 & S2

DIP switches = off

boiler will fire for at least the time set on the "Min. On Time (%)" dial, and then shut off for the remainder of the time set on the "Cycle length" dial. This cycle will be repeated until the outdoor temperature becomes warmer than the "Occupied" dial setting, putting the control back into WWSD. Adjusting the "Occupied" dial shifts the WWSD point and heating curve up or down as shown in Figure 6, and the indoor air temperature will be affected accordingly. The "UnOccupied" dial works the same way as the "Occupied" dial when the control has been put into the UnOccupied mode, except the design outdoor temperature is also shifted down.

Indoor Sensor 074 function

When Indoor Sensor 074s are connected to this control, the control will still operate the boilers based on outdoor temperature, but will also use one 074 sensor input, or the lower reading of two 074s to prevent overheating. With these sensors, the "Occupied" and "UnOccupied" dial settings become the desired indoor air temperatures.

The control will not allow the curve to be shifted up,

if windows or doors are left open. Figure 7 shows how an Indoor Sensor will shift the heating curve and the WWSD point down to prevent overheating, especially in milder weather when a Minimum On Time may cause overheating.

Boiler is cycled on/off

Boiler is turned off

Boiler is turned on 100%

-10°F

-30°F

(-23)°C

(-34)°C

(32)

WWSD

Point

(21)

(10)30(-1)10(-12)

20% minimum on time

Design

Outdoor

Temperature

Outdoor air temperature

Figure 5. Outdoor Reset with a 20% Minimum On Time setting

100%

90%

80%

70%

60%

50%

40%

30%

20%

20% Min. on time selected

10%

Percentage of boiler on time per cycle

0% on time

Boiler is turned off

WWSD Point

(32)

(21)

Figure 6. Shifting the heating curve

Boiler is cycled on/off

20% minimum on time

Design

Outdoor

Temperature

(10)30(-1)10(-12)

Outdoor air temperature

-10°F

(-23)°C

with the Occupied dial

100%

90%

80%

70%

60%

50%

40%

30%

Boiler is turned on 100%

20%

20% Min. on time selected

10%

Percentage of boiler on time per cycle

0% on time

-30°F

(-34)°C

WWSD

(32)

Figure 7. Temporary shift to UnOc-

cupied mode or by Indoor Sensor

If the indoor temp. becomes too warm, the Heating Curve shifts down. After the Heating Cycle, the boiler is kept off until the indoor cools off to the desired room temp.

Boiler is turned off

Point

(21)

Early Start

123 4

Early Start

123 4

Indoor sensors S1 or

S1 & S2 DIP switches = on

Boiler is cycled on/off

20% minimum on time

Design

Outdoor

Temperature

(10)30(-1)10(-12)

Outdoor air temperature

Off

-10°F

(-23)°C

074 room temperature feedback

Steam established

Heating cycle

Early Start

Auxiliary

Boiler

Steam established

Heating cycle

Early Start

Auxiliary

Boiler

Power

WWSD

UnOcc.

Warning

Indoor Sensor S1

Indoor Sensor S2 Condensate Return Sensor

Indoor Sensor S1 Indoor Sensor S2

Condensate Return Sensor

Boiler is turned on 100%

-30°F

(-34)°C

Steam established

Heating cycle

Early Start

Auxiliary

Boiler

100%

90%

80%

70%

60%

50%

40%

30%

20%

20% Min. on time selected

10%

Percentage of boiler on time per cycle

0% on time

Condensate Return Sensor 071 function

Ind

Setting a Minimum On Time for a steam system can become problematic because a system takes more time to reach operating temperature from a cold start than when it is hot from a previous cycle. Use of the Condensate Return Sensor included with the control is highly recommended since the "Steam Established" dial can then be set to match the operating characteristics of the system. The control will turn on its "Boiler" light and fire the boiler for a warm-up period, modifying the cycle to operate as in Figure 8.

Early Start

Establishing Steam

(Warm up)

Power

WWSD

UnOcc.

Warning

Steam established

Heating cycle

Early Start

Auxiliary

Boiler

123 4

Off

oor Sensor

Condensate Return Sensor

Heating Cycle

(on time)

Steam

Power

established

Heating

WWSD

cycle

Early Start

UnOcc.

Auxiliary

Warning

Boiler

Condensate return sensor

DIP switch = on

Steam

Power

established

Heating

WWSD

cycle

Early Start

UnOcc.

Auxiliary

Warning

Boiler

Heating Cycle

(off time)

Steam

Power

established

Heating

WWSD

cycle

Early Start

UnOcc.

Auxiliary

Warning

Boiler

Boiler on

off

Boiler Operation

15 minutes

on time

Boiler off

Steam established - start cycle

45 minutes off time

60 minute cycle

Boiler on

15 minutes

on time

Steam established - start cycle

45 minutes off time

60 minute cycle

Boiler off

220°F

210°F

200°F

190°F

180°F

(Warm-up period)

Establishing Steam

170°F

temperature

160°F

Condensate return

150°F

est.

off

Steam established temperature setting

(Warm-up period)

Establishing Steam

est.

off

140°F

Figure 8. 25% on time with Condensate Return Sensor and "Steam Established" dial set to 170°F

The control will not start to time out the Heating Cycle until the Condensate Return Sensor reaches the temperature set on the "Steam Established" dial. When this occurs, the "Steam Established" light will come on and the control will operate the boiler until the on time of the Heating Cycle has elapsed. This function ensures that steam has been established throughout the system before the Heating Cycle is started. In a two pipe system, most installers will place the Condensate Sensor on the condensate return line of the radiator furthest from the boiler. In one pipe systems the best location is usually on the pipe just before it enters the last radiator. These locations are usually good, but in some larger systems with long runs it may be necessary to place the sensor closer to the boiler so that the first rooms in the system do not overheat. Again, it is important to ensure that the system components are all working properly, since in a properly vented and drained system, steam is established quickly throughout the system during each cycle, and sensor placement is not as critical as in some "problem" systems.

Boiler on

15 minutes

on time

Boiler off

Steam established - start cycle

45 minutes off time

Boiler on

15 minutes

on time

Steam established - start cycle

45 minutes off time

Boiler off

Boiler

Operation

60 minute cycle

220°F

210°F

200°F

190°F

180°F

170°F

160°F

temperature

150°F

Condensate return

140°F

Figure 9. 25% on time with Condensate Return Sensor, "Steam Established" dial set to 170°F and "Lockout Diff'l" set to 30°F

off

Steam established temperature setting

30°F Lockout differential setting

Lockout period

(Warm-up period)

Establishing Steam

est.

60 minute cycle

off

Lockout period

(Warm-up period)

Establishing Steam

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