t
rol operates the boiler burner to maintain the boiler
target at the boiler outlet sensor.
Mode 7 – Designed for an external input signal with
p
rimary/secondary piping. The external input signal
can be provided from a BMS, an EMS or an external
c
ontrol. The external input signal changes the boiler
target according to a linear scale (see Tables O & P).
The control operates the boiler burner to maintain the
boiler target at the system sensor. See Fig. 35.
32
Mode 4 (Not supported) – Outdoor reset using pri-
mary piping. The heater is operated as in Mode 1.
However, the target temperature is based on outdoor
reset.
Mode 5 – Outdoor reset using primary/secondary pip-
ing. The heater is operated as in Mode 2. However, the
target temperature is based on outdoor reset. See Fig.
34.
Mode 6 (Not supported) – Designed for an external
input signal with primary piping. The external input sig-
nal can be provided from a BMS, an EMS or a
sequencing control. The external input signal changes
the boiler target according to a linear scale. The con-
Fig. 35: Mode 7 Primary/Secondary Piping with
External Target Temp
Fig. 34: Mode 5 Primary/Secondary Piping with
Outdoor Reset
0-10 VDC 0-20 mA* Boiler Target
0 0 --- (OFF)
1 2 50°F
2 4 68.9°F
3 6 87.8°F
4 8 106.7°F
5 10 125.6°F
6 12 144.1°F
7 14 163.3°F
8 16 182.2°F
9 18 201.1°F
10 20 220°F
Table O: 0-10 VDC or 0-20 mA External Input Signal
*Requires a 500Ω resistor.
Fig. 33: Mode 3 Dedicated DHW
*Maximum 4 times the pipe diameter or 12”, whichever is less.
*Maximum 4 times the pipe diameter or 12”, whichever is less.
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