22
Arr 2 Auxiliary Heat Source
F
IG
. 7.1
A
A
RR
2 O
PTIONS
IMPORTANT
Arr 2 Heat Circulating
Solar
pump
Aux heat
source pump
Solar
pump
Heat circulating pump
Arr 2
Arr 2 is used for two coil cylinders when the use of both the upper and
lower coils of the cylinder are controlled by the AST 100 Controller (R1
& R2).
There are two ways that this can be done:-
1. Arr 2 Auxiliary Heat Source
The lower solar coil is controlled by the AST 100 Controller, i.e. solar
system is circulated through the lower coil by the solar pump controlled
by R1 - see wiring diagram fig. 6.4A.
*The cylinder upper coil is heated by an auxiliary heat source, this is
also controlled by the AST 100 Controller i.e. the auxiliary heat source
circulating pump is controlled by R2 - see wiring diagram fig. 6.5A.
The pump is switched On by AHO and Off by AHF - see 7.5.20 & 7.5.21.
When Arr 2 is selected extreme care must be taken to ensure the
auxiliary heat source only operates when it will not adversely affect
the cylinder temperature prior to and during the ‘solar day’.
2. Arr 2 Heat Circulating
The lower solar coil is controlled by the AST 100 Controller, i.e. solar system
is circulated through the lower coil by the solar pump controlled by R1 - see
wiring diagram fig. 6.4A.
The upper coil is used to heat a radiator when there is ample or excessive
solar energy. For this a pump is fitted controlled by R2 - see wiring
diagram fig. 6.5A.
The pump is switched On by AHO and Off by AHF - see 7.5.20 & 7.5.21.
Arr 2 is only used for more advanced systems, the installer must
have full appreciation of the system and the way the AST 100
Controller settings affect the auxiliary heat source or heat circulating
system.
IMPORTANT
*Some boilers with integral
circulating pumps are not suitable
for this application - consult Ariston
for further details.
IMPORTANT
