Boiler Controls - Hamworthy Purewell VariHeat 65he Installation, Comissioning And Servicing Instructions

8.0 BOILER CONTROLS

8.1 CONTROLS OVERVIEW
The Purewell VariHeat control system is a self contained, microprocessor based package (Siemens LMU64), con-
trolling and monitoring all safety and functional aspects of the boiler performance and it's integration with external
system controls.
Access to boiler performance information is via the HMI Facia display screen consisting of 2x16 character backlit
LCD unit and 10 buttons for operation and setting of the boiler.
The system is compatible with BMS (or other) external controls via an enable or 0~10V DC input signal. The op-
tional outside and mixed flow sensors are supplied by Hamworthy Heating Ltd to ensure safe and reliable opera-
tion.
The system provides as standard, 2 volt free contacts for external fault indication - Normal Run & General Fault.
The Siemens LMU64 control system allows the connection of multiple boilers to an RVA 47cascade controller to
enable control of up to 12 multiple boilers.
Note: To ensure safe and reliable operation, all wiring between sensors & boilers must be separated from mains
voltage wiring.
HAMWORTHY HEATING LTD
4 2
5 1
Button Function
Reset Lockouts
1
Not Used
2
Selection of Operating Mode
3
Automatic (time control)
Continuous ' Normal' temperature
Continuous ' Reduced ' setback tempera-
ture
Standby - boiler off.
Adjustment of boiler or room temperature
4
Not used
5
Selection of operating parameter
6, 7
Adjustment of parameter value
8, 9
Select Information display screens
10
Figure 8.1 - General Overview of Panel Fascia
PUREWELL VariHeat he
6 7 8
20
3
9 10
500001170/K