BMC and BMC-6X Installation and Operation Manual

OPERATING SETTINGS

PROGRAM CHANGE SETTINGS

To be able to change the BMC settings the Program/Run Switch must be set to Program. The

PROGRAM

 

switch is located under the Enclosure Wiring Cover for security. The Enclosure Wiring Cover

 

can be securely closed using a lock.

 

RUN

SEASON

Winter, Summer

Default: Winter

Button: MENU/Season

 

The BMC will turn all boiler relays off when it is in Summer setting. However, a DHW call will bring boilers back on if needed. The Message Display Line will display Summer to show status.

When in Winter, the BMC will activate the Sys relay whenever the Outdoor temperature (OD) falls to or below the Outdoor Cutoff setting. In addition, it will begin heating whenever the System temperature (SYS) falls below the Set Point Temperature. The Message Display Line will not display any season information when in Winter.

When the heating season is over, it is a good practice to switch the BMC to Summer setting. This will allow DHW calls to operate the boilers when needed.

SET POINT (NOT ADJUSTABLE IN EMS MODE)

Adjustable from 70ºF/ 21ºC to 250ºF/ 121ºC

Default: 140ºF/ 60ºC

Button: MENU/Set Point

 

The Set point is the temperature value the BMC will use to control the system.

It only be available when Set Point is selected as the Sensor Type. See page 14.

The BMC will increase, decrease or hold the modulation of the boilers to maintain the system temperature around the Set point. The amount of fluctuate around the set point depends on the Modulation Mode, System Settings, and Stage Settings.

If the EMS Mode was Enabled, the Set Point will be set by the EMS/BMS system and will be available to be read but not changed on the display.

-------------

SEASON --------------

Winter

 

Summer

 

BACK

SAVE

ALERT

DO NOT turn power off to the BMC when heating season is over. If you do so, the battery will run down and will have to be replaced. Instead, switch to Summer.

------------SETPOINT----------

 

70 F

[]

 

BACK

SAVE

RESET RATIO

Adjustable 1.00ºOD : 4.00ºSys to 4.00ºOD : 1.00ºSys Default: 1.00ºOD : 1.00ºSys

Button: MENU/Set Point

It's only be available when Reset is selected as the Sensor Type. See page 14.

The Reset Ratio determines how the System water temperature (SYS) will vary with Outside temperature (OD). With any of the ratios, the colder it becomes outside, the hotter the temperature of the system water. The ratios are adjustable from 1.00 (OD):4.00 (SYS) to 4.00 (OD):1.00 (SYS). (See Understanding Operation Concept on page 5)

With a 1.00 (OD):4.00 (SYS) ratio, the System water temperature (SYS) will increase rapidly as the outside temperature falls, hitting the maximum of 240°F at 24°F outside temperature. With a 4.00 (OD):1.00 (SYS) ratio, the System water temperature (SYS) will increase slowly as the outside temperature falls. Even at -30°F, the system water will only be 125°F, and at 24°F outside, the system water will be 112°F. Such a low Reset Ratio might be used with radiant floor heating applications.

With most baseboard heating applications, a 1.00 (OD):1.00 (SYS) setting is a good place to start. With a 1.00 (OD):1.00 (SYS) ratio, for every degree the outside temperature falls, the system water temperature is increased one degree.

If required: Adjust the RESET RATIO in cold weather. If the ambient building temperatures are too cold in cold weather, move the ratio to a higher selection. That is, if 1.00 (OD):1.00 (SYS) was initially selected, change the selection to 1.00 (OD):1.25 (SYS). If the building temperatures are too warm in cold weather, move the ratio to a lower selection. That is, if 1.00 (OD):1.00 (SYS) was initially selected, change the selection to 1.25 (OD):1.00 (SYS).

--------- RESET RATIO

----------

1.00

OD=4.00

Sys

1.00

OD=3.00

Sys

1.00

OD=2.00

Sys

1.00

OD=1.50

Sys

1.00

OD=1.25

Sys

1.00

OD=1.00

Sys

1.25

OD=1.00

Sys

1.50

OD=1.00

Sys

2.00

OD=1.00

Sys

3.00

OD=1.00

Sys

4.00

OD=1.00

Sys

BACK

 

SAVE

Temperature

130

1:4

1:1

 

 

 

 

 

 

 

Warmer

 

 

120

 

 

Water

 

 

Colder

110

 

4:1

 

 

 

 

 

100

70 60 50 40 Outdoor Temperature

17

Page 17
Image 17
Weil-McLain BMC-6X operation manual Operating Settings, Season, SET Point not Adjustable in EMS Mode, Reset Ratio