Patterson-Kelley MACH Series Installation & Owner's Manual page 26

MACH® Series Gas-Fired Boiler
temperature controller indicates a call for heat from
the DHW system. When the DHW system calls for
heat, the Central heat pump output (Terminal 10 TB2)
deenergizes and the DHW pump output (Terminal 11
TB2) energizes providing 120 VAC power is provided
to energize a relay coil for the DHW pump. The
DHW status should be set to 1 (DHW system ON).
CAUTION!
Terminal 10 and 11 on TB2 are for pilot duty only.
they should not be connected directly to the
pump.
Outdoor Air Reset (optional):
OU TD OO R A IR vs B OILER SETP O IN T
190
180
170
160
150
140
130
120
110
100
90
80
70
0 10
The control automatically detects the presence of the
outdoor air sensor. If an outdoor air sensor is present,
the boiler automatically defaults to outdoor air reset
for setting boiler temp. The parameters should be set
according to the following table:
Item
Maximum Setpoint
Minimum Setpoint
Outdoor Air
Minimum Temp.
Outdoor Air
Maximum Temp.
Boiler Shutoff Temp.
Outdoor Air Offset
Boiler Configuration
The set point of the boiler is controlled by an outdoor
temperature sensor. As the outdoor temperature falls
the setpoint of the boiler is increased. The boiler
modulates to maintain this setpoint.
The setpoint is adjusted according to the above
parameters. The boiler setpoint will be the maximum
value (180° F) when the outdoor air is at or below a
minimum temperature value (20° F). The boiler
setpoint will be at the minimum value (80° F), when
outdoor air is at or above a maximum temperature
value (70° F). The setpoint for "in between" values
of outdoor air temperature, is linearly proportional to
Page 22
20 3 0 40 50 60 70
OUTDOOR AIR TEMP °F
Parameter Value
° F
4 180
5 80
6 20
7 70
10 90
12 0
34 01
Installation
8 0 9 0
Allowable
Range ° F
68-185
60-140
4-50
59-77
32-140
(32=off)
0-144