Lochinvar SMART SYSTEM 502 - 2072 - Manual (Page 19)

1
Service
(continued)
19
F6: Outdoor air shutdown differential
The outdoor air shutdown differential parameter is the number
of degrees below parameter F5 the outdoor air temperature must
go before the unit will respond to a SH demand. This parameter
can be changed by the user or the installer by accessing
parameter F6. The temperature range of this parameter is 0°F
(0°C) to 90°F (50°C). The default value is 10°F (5°C).
F7: Shift reset curve
The shift reset curve parameter shifts the actual set point above
or below the calculated set point the number of degrees in this
parameter. This parameter can be changed by the installer
by accessing parameter F7. The temperature range of this
parameter is -27°F (-15°C) to 27°F (15°). The default value is
0°F (0°C). This feature will be active if this parameter is set to
anything other than 0°F (0°C).
F8: Boost temperature
If a SH demand lasts longer than the programmed time delay
setting (F9) and there have been no DHW demands, the control
will increase the SH set point by the amount in this parameter.
If the SH demand continues through another time period,
the set point will be increased again. This will continue until
either the SH demand ends, a maximum of 20 increases has
occurred, or the SH user set point has been reached. Once the
SH demand has been satisfied the set point will revert back to
its calculated setting. The boost temperature can be changed by
the installer by accessing parameter F8. The temperature range
of this parameter is 0°F (0°C) to 45°F (25°C). The default value
is 0°F (0°C). This feature will be active if this parameter is set to
anything other than 0°F (0°C).
F9: Boost time
The boost time parameter sets the amount of time that must
elapse with a SH demand before the water temperature set point
will be increased. This parameter can be changed by the installer
by accessing parameter F9. The time range for this parameter is
1 minute to 250 minutes. The default value is 20 minutes.
G: Anti-cycling
G1: Anti-cycle delay
Once a SH demand has been satisfied, a set amount of time must
elapse before the control will respond to a new SH demand. The
control will block the new heat demand and anti-cycling will
be shown in the display until the time has elapsed or the water
temperature drops below parameter G2. This parameter can be
changed by the installer by accessing parameter G1. The time
range for this parameter is 0 minutes to 40 minutes. The default
value is 1 minute.
G2: Anti-cycle override differential
The control will bypass the anti-cycling time if the water
temperature drops too quickly. The control will use the water
temperature at the time it shut off as the starting point.
If the temperature drops below the temperature parameter
the control will abort anti-cycling and allow the unit to fire.
This parameter can be changed by the installer by accessing
parameter G2. The temperature range of this parameter is 0°F
(0°C) to 54°F (30°C). The default value is 10°F (5°C).
G3: Ramp delay enable
When the ramp delay on/off parameter is active, the ramp
delay limits the boiler firing rate when a SH cycle has started.
There are six (6) limiting steps used to limit temperature
overshoot and short cycles, see FIG. 1-2 on page 19 of this
manual. This feature can be turned on or off depending on the
installation. This parameter can be changed by the installer by
accessing parameter G3. The control range of this parameter
is 0 = Off, 1 = Ramp Up Only, and 2 = Ramp Up and Ramp
Down. The default value is 0.
G4: Ramp delay settings
When ramp delay is active, there are up to six (6) limiting
steps, as described above in Ramp Delay On/Off. Each step has
its own time period and modulation limit. The installer can
adjust these settings by accessing parameter G4. The settings
for each step are displayed as follows:
G4 Ramp n
mm minutes ppp.p%
Where n is the number of the step, mm is the length of time
in that step, and ppp.p is the maximum firing rate allowed
during that step. Upon selecting this parameter, the ramp
number n will be flashing. Use the UP and DOWN keys
to select the step you wish to adjust. Use the NEXT and
PREVIOUS keys to select the setting you wish to adjust. Use
the UP and DOWN keys to adjust the value of each setting.
NOTE THAT THE FIRING RATE LIMIT IN STEP 6 WILL
APPLY THROUGHOUT THE ENTIRE CALL FOR HEAT. If
100% rate is required, the rate limit in step 6 must be 100%.
The default values are 2 minutes at 50% for step 1, 1 minute
at 80% for step 2, and 1 minute at 100% for steps 3 through 6.
G5: Minimum on / off stages 1, 3
Whenever Stage 1 or Stage 3 (if used) starts or stops, a timer is
started. This timer must expire before that stage can turn off
or back on. To adjust this time delay, access parameter G5.
The range of this parameter is 0 to 255 seconds. The default
value is 60 seconds.
G6: Delay between stages 1, 3
Whenever Stage 1 or Stage 3 (if used) turns on, a timer must
expire before another Stage 1 or 3 can turn on, whether in the
same heater, or in another heater in a Cascade. To adjust this
time delay, access parameter G6. The range of this parameter
is 0 to 255 seconds. The default value is 60 seconds.
Copper-fin II/IIE Boiler, Water Heater and Pool Service Manual