PB Heat Peerless Combi 160, User Manual

Page: 74 / 107

74
12 - USE
12.10.2 - Outdoor reset
adjustment precautions
When making adjustments to change
the supply temperature, it is advisable
to fi rst set the suggested default values
for the desired curves shown in fi gures
63 and 64. If these default values
do not produce a satisfactory result,
then proceed to make the appropriate
adjustments bearing in mind that:
A - each parameter must be varied
gradually;
B - after each parameter change, wait
at least 24 hours in order to see the
result;
C - the closer the adjustment curve
matches the actual load of the
building, the greater the comfort and
the energy savings will be;
D - knob “7” in fi gure 62 can be used
to make the small line shifts, “b”,
shown in fi gures 63 and 64. These
shifts will change the supply water
temperature up to 18 °F
(10 °C) .
12.10.3 - Outdoor reset:
setting parameters
Refer to section 12.16 and set:
- = “The angle of the curve”,
which can be adjusted between 0.1
and 5.0. Suggested starting values
are: 0.6 for “low temperature” systems;
1.6 for “high temperature” systems;
- = “Minimum heating tempera-
ture”. When the calculated tempera-
ture drops below this value the
heating service stops. The range of
adjustment is between 68 °F (
20 °C)
and 140 °F (60 °C) . The suggested
starting values are: 86 °F (30 °C) for
“low temperature” systems; 104 °F (40
°C) for “high temperature” systems;
- = “Maximum heating
temperature”. This parameter
is the limit of the supply heating
temperature. Its range of adjustment
is between 86 °F
(30 °C) and 194
°F (90 °C) . The suggested starting
values are: 113 °F (45 °C) for “low
temperature” systems; 176 °F (80 °C)
for “high temperature” systems.
Refer to section 12.11and set:
- = “Reaction” of the calculated
temperature with respect to the
outdoor temperature input. The
range of adjustment is between
1 °F
(1 °C) and 18 °F (10 °C) . A
low “Reaction” value results in a
constant dwelling temperature
but extended time in reaching full
running conditions and responding to
outdoor temperature changes. A high
“Reaction” value results in reaching
full running conditions quickly, but
may cause oscillations in the dwelling
temperature.
It is advised to maintain a “Reaction”
value between 1 and 2;
- = “Fix point” is the heating
calculated temperature, when the
outdoor temperature is 68 °F
(20 °C) .
It is called “Fix Point” because it is
also the angle fulcrum of the curve.
The suggested starting values are:
92 °F
(33 °C) for “low temperature”
systems 122 °F (50 °C) for “high
temperature” systems.
12.10.4 - Outdoor reset:
zone adjustments
The default values previously
suggested are for boilers using
an outdoor temperature sensor
installed in dwellings with average
heat loss in areas where the outside
temperature for the calculation of the
heat requirement is 23 °F
(-5°C) . In
the event that the climatic zone is
different, adjust the gradient of the
curve, parameter , to obtain a
calculated temperature of 176 °F (80
°C) for high temperature systems,
see fi gure 63. For “Low Temperature”
systems adjust the gradient of the
curve, parameter , to obtain
a calculated temperature of 113 °F
(45°C) , see fi gure 64.
12.10.5 - Outdoor reset
activation
Once selected, reset adjustment is
completely automatic and will switch
off at the end of the heating season
and switch back on at the beginning
of the heating season. When the
“Calculated temperature” is lower than
the “Minimum heating temperature”,
parameter , the heating service
switches off. When the “Calculated
temperature” exceeds the “Minimum
heating temperature”, parameter
, the heating service switches back on.
If for some reason the heating service
doesn’t match the load, use knob “7” in
fi gure 62, to raise or
lower the calculated temperature
and match the “Minimum heating
temperature” on an advanced or
delayed basis.
12.10.6 – Outdoor reset
with room compensation
While in the “Installers’ Menu” set the
parameter to 02, see section
12.17. The system will function exactly
as described in the previous “Outdoor
reset adjustment” sections except
that now the boiler pump will stay on
permanently. The opening of the room
thermostat contacts will translate into
a parallel downward movement of the
curve in fi gure 63 or 64. The value by
which the curve moves downwards can
be adjusted by the parameter
present in the “Installers’ Menu”, see
section 12.17. The parameter
can range from 1 °F (1 °C) to 36 °F,
(20°C) . The suggested values for this
parameter are:
- 18 °F
(10°C) for high temperature
radiator systems;
- 6 °F
(3°C) for low temperature radiant
panel systems
Values of this parameter that are
too high may translate into room
temperature instability. Values that are
too low may make the action of the
room thermostat ineffective. Climatic
adjustment with room compensation can
be used in all the systems described in
section 12.10.1. The advantage being
that the constant running of the pump
will stabilize and standardize the room
temperatures. This is especially true
when some loops in the heating system
have considerably greater volume than
others.