AERCO BMS II BOILER - Manual (Page 52)

PROGRAMMING BMS II
4-2
Selecting Outdoor Reset Mode
The Outdoor Reset Mode is selected using the Header Set Mode option in the Field Adjust Menu as
follows:
1. Using the keypad on the BMS II, press the MENU key, until FIELD ADJUST MENU appears in the
display.
2. Using the
▲ or ▼ arrow key on the keypad, scroll through the menu until HEADER SET MODE is
displayed in the first line of the VFD display. The second line of the display will show the currently
selected Header Set Mode (CONSTANT SETPOINT, OUTDOOR RESET or REMOTE SETPOINT).
3. If OUTDOOR RESET is not displayed in the second line of the display, press the CHANGE key. The
VFD display will switch to a reverse video format indicating that a change is in process.
4. Using the
▲ or ▼ arrow key, select OUTDOOR RESET.
5. Press the ENTER key to store the change. The reverse video display will revert to the normal display
format indicating that the change has been store in memory. While still in the Field Adjust Menu,
proceed to the next paragraph and continue the set-up procedure.
Determining Reset Schedule
There are two variables that must be considered when determining Reset Schedule: Reset Ratio and
Building Reference Temperature. There are two methods for determining the Reset Ratio. The first
method utilizes the Reset Ratio Charts provided in Appendix C. This method is suitable for most
installations. However, if a special Reset Schedule is desired for reheat or other purposes, the calculation
method must be used. When using this method, both Reset Ratio and Building reference Temperature
must be calculated. Refer to Appendix C for further instructions concerning both of these methods.
Once the Reset Ratio and Building Reference Temperature have been determined, proceed to the next
paragraph and enter these options.
Entering Reset Ratio and Building Reference Temperature
The Reset Ratio and Building Reference Temperature (BLDG REF TEMP) are also entered using options
contained in the Field Adjust Menu. These parameters are entered as follows:
1. To enter the required Reset Ratio, scroll through the Field Adjust Menu and select RESET RATIO.
2. If the desired ratio is not displayed, press the CHANGE key. The display will switch to a reverse video
format indicating that a change is in process.
3. Select the required Reset Ratio using the
▲ or ▼ arrow key.
4. Press the ENTER key to store the change. The reverse video display will revert to the normal display
format indicating that the change has been store in memory.
5. Next, scroll through the Field Adjust Menu and select BLDG REF TEMP.
6. If the desired BLDG REF TEMP is not displayed, press the CHANGE key. The display will switch to a
reverse video format.
7. Select the required BLDG REF TEMP using the
▲ or ▼ arrow key.
8. Press the ENTER key to store the change. The reverse video display will revert to the normal VFD
display format.
9. This completes the required entries in the Field Adjust Menu. Proceed to the next paragraph and
select the Boiler Operating Mode.