Hamworthy PUREWELL VariHeat he, Инструкция по установке, пусконаладке и обслуживанию

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HAMWORTHY HEATING LTD
22
PUREWELL VariHeat he 500001155/F
8.5.2 Cascade
This function is only operational when the relevant parameter has been set. The BIC930 control can operate
upto 8 modules in cascade control with one module having to be designated Master and the others as Slaves.
Each module will require setting up.
8.5.2.1 Communication
When a Slave has been connected to the bus, the Master (0) detects the connected Slave by it’s unique ad-
dress( 1...7). Should a connected Slave be at lockout or not recognised by the Master, it will not participate in
the cascade. However, if the Slave is switched Off by the On/Off button, it will still participate and the Master will
adjust the cascade acknowledging the loss of capacity.
In communication between the Master and Slaves, having sent a message, the Slave will respond within 0.5
seconds. If the response fails the first time or the response is corrupted, the Master will resend the message. If
the response fails again, the Master will remove the Slave from the cascade and adjust the capacity amongst
the Slaves responding. The Master will then check for a correct response from all Slaves every 15 seconds.
8.5.2.2 Cascade Regulation
Regulation of the heat demand is based upon the actual flow temperature and the desired set-point, calculated
by the heat curve and User setting. Should there be no mixed flow sensor fitted, the Master will allow all Slaves
to operate at maximum power
Adjustment of the proportional band and integral gain parameters is possible depending upon the installation.
With the cascade running two or more boilers, should the flow temperature exceed the set-point, the cascade
will try and manage the temperature to the set-point by switching off the boilers until only one boiler is firing. At
which point the blocking function will be implemented until the flow temperature is below the hysteresis level.
Should a Slave not receive a message from the Master (due to a problem with that boiler) within 20 seconds,
provided that the Remote On/Off input is closed, the Slave will allow the boiler to operate as a stand alone boiler
on it’s own thermostat set-point.
8.5.2.3 Cascade Sequence
The cascade sequence is changed every 24 hours to spread boiler running hours . However during the first 48
hours from initial switch on, the sequence is changed every hour to prevent deposition in any one boiler - see
figure 8.5.2.3.
Day Switch ON Sequence Switch OFF Sequence
Day n M-S1-S2-S3-S4-S5-S6-S7 S7-S6-S5-S4-S3-S2-S1-M
Day n+1 S1-S2-S3-S4-S5-S6-S7-M M-S7-S6-S5-S4-S3-S2-S1
Day n+2 S2-S3-S4-S5-S6-S7-M-S1 S1-M-S7-S6-S5-S4-S3-S2
Day n+3 S3-S4-S5-S6-S7-M-S1-S2 S2-S1-M-S7-S6-S5-S4-S3
- - etc.- - - - etc.- - - - etc.- -
Figure 8.5.2.3 - Cascade Sequence