83
21.9.10
A
LTERNATE
L
EADER
This parameter allows the Member 1 boiler to automatically assume control of the Cascade should it lose
communication with the Leader boiler. When programmed to YES, it is recommended that the Member 1 boiler
have its own set of external sensors installed (such as the system supply sensor), to maintain the same level of
temperature control as with the Leader boiler. Voltage signals (such as the 0 - 10V system pump speed input) can
be connected to both boilers.
Do not connect the sensors connected to the leader boiler to the member 1 boiler. The actual
water temperatures will be higher than expected, which could lead to property damage and/or
personal injury..
When communication is re-established with the Leader boiler, Member 1 will automatically relinquish control of the
Cascade to the Leader boiler.
The default value of this parameter is NO.
21.9.11
B
OILER
S
IZE
When boilers of different sizes are connected together in a Cascade, the Leader boiler has to know the size of each
boiler in that Cascade. The Boiler Size parameters allow the installer to program the size based on the Cascade
address. This screen shows the Cascade address and the size of the boiler with that address (in Btu/hr):
1.
When the Boiler Size screen is first accessed, Cascade Address (SELF) is shown.
2.
Press the NAVIGATION dial twice to access the Input setting. Rotate the NAVIGATION dial to
increase the boiler input. Input settings 0 - 400 Btu/hr can be adjusted in increments of 5 (5000 Btu/hr).
When the closest approximate boiler size is shown, press the RIGHT SELECT [SAVE] key.
3.
Rotate the NAVIGATION dial to select the address of the next boiler in the Cascade. Repeat Step two
above.
4.
Once the size of the last boiler in the Cascade has been entered and saved, press the LEFT SELECT
[EXIT] key to return to the Control Modes menu.
5.
If no other parameters are to be adjusted, press the RIGHT SELECT [HOME] key to save the new settings
and return to the Status screens.
The SMART SYSTEM control automatically uses the Efficiency Optimisation Cascade type when controlling boilers of
different sizes.
21.10
BUILDING MANAGEMENT SYSTEM (BMS)
21.10.1
BMS
The set point or modulation of the boiler may be controlled through the 0 - 10V BMS input, BACnet, or ModBus.
When the BMS parameter is set to INACTIVE, the 0 - 10V input will be ignored. When set to ACTIVE, the set point or
modulation will be controlled by the voltage on the 0 - 10V input (in the case of 0 - 10V BMS control), or the 0 - 10V
input value received through ModBus or BACnet. The default value is INACTIVE.
21.10.2
BMS
T
YPE
When programmed for BMS control through the 0 - 10V BMS input or through ModBus/BACnet, the 0 - 10V signal
can be interpreted as either a modulation command or a set point. When the BMS Type parameter is set to POWER,
the 0 - 10V signal will control the modulation. When set to SETPOINT, the 0 - 10V signal will control the SH set
point. The default setting is SETPOINT.
Summary of Contents for HERALD HCB116CE
Page 8: ...8 3 1 2 PRINCIPLE PARTS TO BE USED IN CONJUNCTION WITH TABLE 3 1 1...
Page 31: ...31 Max distance between brackets...
Page 32: ...32...
Page 33: ...33...
Page 37: ...37...
Page 53: ...53 15 8 WIRING DIAGRAM 15 8 1 WIRING DIAGRAM...
Page 54: ...54 15 9 LADDER DIAGRAM 15 9 1 LADDER DIAGRAM...
Page 92: ...92...
