Bryan Boilers & 300 ユーザーズマニュアル

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Date:  
8-4-2010 
 
Revision: 0 
 
Form:  
2396
 
that way until the 4- 20mA signal is stable again. 
 
LL CH 20MA WATER TEMPERATURE: 
TEMPERATURE OR NONE 
 
CH 4MA WATER TEMPERATURE: 
TEMPERATURE OR NONE 
These provide the 20mA and 4mA temperatures 
for the interpolation curve. If either of these have 
the None value, are invalid, are out of range, or 
are too close for interpolation, an alert is issued 
and the setpoint reverts to "Local"  when it is 
selected as 4-20mA. 
 
LL CH SETPOINT: DEGREES OR NONE 
This setpoint is used when the time-of-day input 
is off. If  the ODR function is inactive then the 
setpoint is used as-is.  If the ODR function is 
active then this setpoint provides one coordinate 
for the outdoor reset curve. 
 
LL CH TOD SETPOINT: DEGREES OR NONE  
This setpoint is used when the time-of-day input 
is on. If the ODR function is inactive then the 
setpoint is used as-is. 
 
If the ODR function is active then this setpoint 
provides one coordinate for the shifted (because 
TOD is on) outdoor reset curve. 
 
TIME OF DAY 
The Time of Day has one sources of control: a 
switch contact. Closed TOD is an on condition; 
open, then TOD is off. 
 
OUTDOOR RESET AND BOOST (BOOST IS 
FUTURE) 
The outdoor reset and boost functions for the LL 
CH functions will be implemented as described 
for a stand-alone CH loop. 
 
Each of the loops which implements outdoor 
reset and boost has its own parameters. The 
parameters used by the LL master are: 
• LL setpoint 
• LL CH TOD Setpoint 
• LL Outdoor reset enable: Disable, enable 
• LL CH ODR minimum outdoor degrees or 
None 
• temperature: 
• LL CH ODR maximum outdoor degrees or 
None temperature: 
• LL CH ODR low water temperature: degrees or 
None 
• LL CH ODR boost time: mm:ss or None 
• LL CH ODR boost max setpoint: degrees or 
None 
• LL CH ODR boost step: degrees or None 
• LL CH ODR boost recovery step time:mm:ss or 
None 
 
The outdoor reset function requires the outdoor 
temperature. This temperature may be obtained 
from either a local sensor or a LL slave as 
described earlier. If the outdoor temperature is 
invalid and unknown, then no outdoor reset 
action occurs and an alert is issued indicating an 
invalid outdoor temperature. 
 
LL CH ODR MINIMUM WATER 
TEMPERATURE: DEGREES OR NONE 
 
This specifies the minimum outdoor reset 
setpoint for the LL master. If the outdoor reset 
function calculates a temperature that is below 
the temperature specified here, then this 
parameter's temperature will be used. If this 
parameter is invalid or None then the outdoor 
reset function will be inhibited and will not run: if 
it is enabled then an alert is issued. 
 
4.7.6 D
EMAND AND 
R
ATE
 
 
On/Off Hysteresis 
Includes hysteresis shifting 
at turn-on, turn-off 
 
LL OFF HYSTERESIS: DEGREES OR NONE 
 
LL ON HYSTERESIS: DEGREES OR NONE 
 
The LL hysteresis values apply to all setpoint 
sources. The behavior of the hysteresis function 
is identical to the behavior of the stand-alone CH 
hysteresis function, except: 
 
• where stand-alone CH hysteresis uses the 
on/off status of a single burner, the LL hysteresis 
uses the on/off status of all slave burners: this 
status is true if any slave burner is on, and false 
only if all are off. 
• where stand-alone CH hysteresis uses time of 
turn-on and turn-off of a single burner, the LL 
hysteresis uses the turn-on of the first slave 
burners and the turn-off of the last slave burner.  
 
LEAD LAG PID  
The behavior of the Lead Lag PID function is 
identical to the behavior of the stand-alone CH 
PID function. The same gain scalars and 
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