Service manual

24
Pump Delay
Boiler post pump time after burner has
shut off, in seconds.
OFF, 0:20 to 9:55
min, On
Default = 1:00 min
Warm
Weather
Shutdown
Temperature
Warm weather shutdown temperature
using outdoor reset.
35 to 105
o
F, OFF
(2 to 41
o
C, OFF)
Default = 0:20 min
Temperature
Units
Select the desired unit of measurement
o
F,
o
C
Default =
o
F
13.2.10 MODE 6: EXTERNAL TARGET TEMPERATURE USING BOILER INLET SENSOR
The external input signal can be provided from a BMS, EMS or a Tekmar tN4 System Control. The external input
signal creates an internal demand and changes the boiler target according to a linear scale. The BTC 1 modulates
the boiler to maintain the boiler target at the inlet sensor.
An internal heat demand is generated when an analog positive 2-10VDC signal is applied to the +V input and a
negative DC signal is applied to the Com/- input.
If the inlet sensor is ½ (half) of the differential below the Boiler Target, the BTC 1 then changes the proportional
modulation output to the START modulation setting, the Stage contact (pins 15 & 16) closes to proceed to trial for
ignition. The burner remains at minimum modulation until the flame is proved and then the modulating output
changes the boiler burner output to maintain the programmed boiler target temperature at the inlet sensor. If the inlet
sensor reaches ½ (half) of the differential above Boiler Target, the burner goes to minimum fire. Once the external
heat demand is removed, the BTC 1 turns off the appliance and operates the boiler pump based on the PUMP
DELAY setting.
The auto re-set limit is set to 210°F and is fixed. In addition to the auto reset limit the factory installs a manual re-set
limit set to 250°F.