EVCO | 21.10.2020 | AZ
| 31
144EJBSI104
EVLJBOX HP Sequencer -
Application manual
Slave on/off sequence
MODBUS communication enables the sequencer to obtain the alarms and status of every single slave.
When an active unit is in a blocking alarm situation or is switched off, the application instantly activates the first available
unit, fulfilling the system’s request for heat regulation.
The on/off sequence is based on the operating hours of the single slaves. It is possible to view them in the “servicer menu”
--> counters section
.
Irrespective of the number of active slaves, the first slave to be activated will be the one with the lowest number of operating
hours, while the first one to be switched off will be the one with highest number of operating hours.
The application also rotates the slaves following a timing set by the consecutive operating parameter
Pr04
.
If a slave is active for longer than the value set by parameter
Pr04,
the operating hours of the available slaves are checked:
–
If there is a slave with a lower number of operating hours than the active slave, the active slave will be switched off and
the other one activated
–
If there is no slave with a lower number of operating hours than the active slave, the slave which is already operating
will remain active and a control will be carried out after a further consecutive period of operation
Pr04
.
Slave status
Each of the five configured slaves may be in one of the following status:
1. Disabled:
the slave has not been configured in the system
2. Alarm:
a blocking alarm has occurred in the slave so it is not available for regulating the sequencer
3. Off:
the slave is off and is not available for regulating the sequencer
4. Ready:
the slave is available and ready for regulation
5. Active:
the slave is currently regulated by the sequencer
6. Full power:
the slave is at maximum regulation
Mixing valves
The application also manages two mixing valves to control temperature:
–
one for the evaporator which is enabled by parameter
PG03
–
one for the condenser which is enabled by parameter
PG04
The type of regulation used is proportional-integral and loads a dedicated set of parameters according to the operating
mode set by parameter
MOdE
.
When regulating, it is possible to select either the input or output probe of the exchanger through the following parameters:
–
PE01
for the evaporator
–
PC01
for the condenser
It is also possible to configure inversion of the analogue inputs and outputs between the two valves in winter mode through
parameter
Pr05
. The following configurations are possible:
–
Pr05 = 0
- inputs only
only the regulation probes of the valves will be inverted.
The regulation of the evaporator will be based on the condenser probe and vice versa
–
Pr05 = 1
- outputs only:
the analogue outputs of the valves will be inverted.
The regulation of the evaporator will affect the analogue output of the condenser and vice versa
–
Pr05 = 2
- inputs and outputs:
both the analogue inputs and outputs of the valves will be inverted.
