Laars Pennant PNCH Installation And Operation Instructions Manual page 39

Pennant
( 500-2000 )
time selected after the heat demand in the system is
satisfied. This setting also affects the 24VAC output
on the "PMP" "PMP" terminals (see Section 5.2).
These terminals can power a contactor for a larger
system pump. Laars recommends a minimum pump
delay setting of 5 minutes. See Section 6.4.6 for more
information.
NOTE: In modes other than mode 6, the pump will run
continuously if the "HtD" and "ComD" terminals are
jumpered and not connected to a zone valve or pump
end switch, or other "contact closure" device to indicate
when the heat demand in the system is satisfied. The
pump will never run, and the boiler will never fire, if the
jumper is removed and the terminals left empty.
OUTDOOR RESET OUTDOOR RESET OUTDOOR RESET (modes 4 and 5): Outdoor reset
OUTDOOR RESET OUTDOOR RESET
adjusts the target temperature based on the outdoor air
temperature and reset ratio. The reset ratio is
determined from the Boiler Start, Boiler Design,
Outdoor Start and Outdoor Design settings.
HEAT DEMAND HEAT DEMAND HEAT DEMAND – For heat demand to exist, there
HEAT DEMAND HEAT DEMAND
must be continuity between the Com D (common
demand) and Ht D (heat demand) terminals. The
Pennant ships with a jumper between these terminals.
The control also evaluates the sensor(s) installed
in the system. If the control is not in warm weather
shutdown (WWSD), and the sensor(s) are below the
target temperature, the "Dem" segment is turned on in
the display. The control energizes the pump (on pump
mounted boilers) and energizes both "PMP" terminals.
The pump symbol appears in the display (see Figures
25 and 26). The control then operates the stages to
maintain the setpoint temperature.
Boil Start (Boiler Start): The BOIL START Boil Start Boil Start Boil Start Boil Start
temperature is the theoretical boiler supply
temperature that the heating system requires when the
Figure 26. Temperature Control Symbol Description.
outdoor air temperature equals the OUTDR START
temperature setting.
EXAMPLE 1
DHW (Mode 3) Programming. For domestic
hot water systems up to 175°F / 79°C, use mode 3 as
described below.
Step 1: Install the additional sensor into the
storage tank, wiring it to "SC2" and "SUPS" terminals
on the field wiring panel (Figure 23).
Step 2: Press the three programming buttons to
enter ADJUST ADJUST ADJUST ADJUST ADJUST mode (Figure 25). Press ITEM
the programming item, and the arrow keys to adjust the
TARGET TANK TARGET TANK
setting. TARGET TANK TARGET TANK TARGET TANK is desired tank temperature.
Recommended settings with a desired tank temperature
of 125°F:
Example DHW Programming
Item
MODE
BOIL TARGET
TARGET TANK
DIFF TANK
BOIL MASS
DIFF
DLY
F°
Step 4: See Section 6.4.11 Limit Controls. Set
both high limits 25°F / 14°C higher than BOIL TARGET
to allow for temperature rise across heat exchanger.
Manual high limits on water heaters have a maximum
200°F / 93°C setting. (If water must be at 175°F /
79°C or higher with a volume water heater model, use
mode 1. For volume water applications exceeding
200°F / 93°C, contact the factory.)
Fine tuning: For faster staging, increase BOIL
TARGET TARGET DIFF TANK DIFF TANK
TARGET setting. Larger DIFF TANK TARGET TARGET DIFF TANK DIFF TANK and DIFF
will slow response to demand, but may save energy.
If unit short cycles, enter Advanced Programming
mode (Section 6.4) and increase BOILER MAX
the BOIL TARGET BOIL TARGET BOIL TARGET BOIL TARGET setting or higher. Set BOILER MIN BOIL TARGET
STGMODE STGMODE
120°F / 49°C, and STGMODE STGMODE to PID STGMODE
Advanced Programming Mode to enter Advanced
Programming mode, or contact the factory for
assistance.
Figure 27. Temperature Control Target Temperature
Graph.
Page 39
ITEM ITEM ITEM to select ITEM
F° C°
3 3
140°F 60°C
125°F 52°C
2°F 1°C
1 1
2°F 1°C
5:00 5:00
F° °C
BOIL TARGET BOIL TARGET BOIL TARGET BOIL TARGET
BOIL BOIL
BOIL BOIL
DIFF DIFF
DIFF DIFF settings
BOILER MAX BOILER MAX BOILER MAX BOILER MAX setting to
BOILER MIN to BOILER MIN BOILER MIN BOILER MIN
PID PID
PID PID. See Section 6.4.12