Weil-McLain BCP-3 - Manual (Page 9)

9
BCP-3 Installation and Operation Manual
Outdoor Reset Mode
•
When Output-On is selected, the BCP-3 will energize all boiler and system relays when the System reads SHORT or OPEN and
Outdoor is below Outdoor Cutoff. Thus, all boilers will run on their limits. However, if the Outdoor sensor fails and the Outdoor
reads
SHORT or OPEN, the BCP-3 will change the Target Set Point to the Max Water Temperature.
• When Output-Off is selected, the BCP-3 will turn all boilers Off when the System sensor reads SHORT or OPEN. However,
when the Outdoor sensor reads SHORT or OPEN, the BCP-3 will change the Target Set Point to be the Min Water Temperature.
Set Point Mode
•
When Output On is selected, the BCP-3 will turn all boilers On when the System sensor reads SHORT or OPEN.
• When Output-Off is selected, the BCP-3 will turn all boilers Off when the System sensor reads SHORT or OPEN.
• The Outdoor Sensor fault status will not affect the control operation in Set Point mode. And, no Outdoor Cutoff will be available.
Setting the Control to Factory Default
To Reset the BCP-3 control to its original factory defaults, power down the control. Hold down the
SET and DOWN buttons while powering the control back up until the Loading Default Values screen
appears. The Display will direct you to the Startup menu after the defaults are loaded to program the
control.
SET SET
Loading Default
Values...
NOTE: When resetting the control to original factory defaults all control settings will be over written and will no longer exist.
Default Display
The default display will show the current System temperature and the Target temperature. By clicking
the Up or Down button, the display will show the current Outdoor temperature and the Outdoor
Cutoff.
SYSTEM= 148 F
TARGET= 150 F
SET SET
SET SET
Outdoor= 48 F
Cutoff= 65 F
Operating Menu Options (Click SET Button)
Set Point (Available when Startup Control Mode = Set Point)
Options: From -30ºF/-34ºC to 250ºF/121ºC Default: 140ºF/60ºC
SET SET /Set Point
• The Set Point option provides the user with an adjustable fixed Target temperature to control the
system. If an Outdoor Sensor was connected, the next menu option will show Outdoor Cutoff.
Otherwise, there will be no Outdoor Cutoff option.
• The Set Point less the Differential should be set above the boiler manufacturer minimum water
temperature requirements to protect the boilers.
Set Point:
140 F 160 F
SYSTEM= 68 F
TARGET= 160 F
Outdoor Reset (Available when Startup Control Mode = Outdoor Reset)
Options: From 1(8.00º/1.00º) to 12(1.00º/4.00º), and Custom Default: 7(1.00º/1.00º)
SET SET /<Out. Reset>/Reset Ratio
• The Reset Ratio determines how the System Target temperature will vary with Outdoor
temperature changes. The colder it gets outside, the hotter the Target will be. The Ratio is
measured as; Outdoor (O): System Water (S).
• With a 1.00:4.00 ratio, the System water temperature will increase rapidly as the outside
temperature falls hitting the maximum default water temperature of 240°F at 35°F outdoor
temperature. With a 4.00 (O):1.00 (S) ratio, the System water temperature (S) will increase
slowly as the outside temperature (O) falls.
• The Reset Ratio controls the amount of heat entering the heating system based on the outdoor
temperature. A higher numbered Reset Ratio will result in a higher Calculated water temperature.
See the Reset Ratio chart on page 2. If the application has radiant heat, a lower numbered Reset
Ratio curve should be selected. See Type of Radiation in Building Table on page 2.
• Reset Ratios are adjustable based on the building and application. See suggested ratios on page 2.
Reset Ratio O/S:
Custom
1(8.00 / 1.00)
2(4.00 / 1.00)
3(3.00 / 1.00)
4(2.00 / 1.00)
5(1.50 / 1.00)
6(1.25 / 1.00)
7(1.00 / 1.00)
8(1.00 / 1.25)
9(1.00 / 1.50)
10(1.00 / 2.00)
11(1.00 / 3.00)
12(1.00 / 4.00)