Patterson-Kelley MACH-05 - Manual (Page 28)

MACH® Series Gas-Fired Boiler Installation
Page 24
Analog Input to Adjust Setpoint:
Analog Input S etpoint
0
50
100
150
200
0 1 2 3 4 5 6 7 8 9 10
V oltage
Bo
il
e
r S
e
tp
o
in
t
B oiler Setpoint
Non adjustable C urve
The control must be configured for a remote analog
input setpoint according to the following table:
Item Parameter Value
°F
Allowable
Range °F
Maximum Setpoint 4 180 68-185
Minimum Setpoint 5 80 60-140
Boiler Configuration 34 03
The setpoint of the boiler is controlled by an external
0-10 VDC signal. A signal of at least 0.5 VDC is
required to start the boiler. At 0 VDC the setpoint is
32° F; at 10 VDC the setpoint is 212° F. This setpoint
is low and high limited by maximum and minimum
setpoint parameters. The controlled setpoint voltage
range narrows when these limits are used. If the above
tables values are used the boiler setpoint will be 80° F
when the voltage is anything less than approximately 3
VDC. It will then increase linearly with voltage until
approximately 8.5 VDC when it will be 180° F. The
setpoint will remain at 180° F even if voltage is
increased further.
Analog Input to Control Firing Rate:
Analog Input Firing Rate
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 1 0
V oltag e
Fi
ri
n
g
R
a
te
The control must be configured for analog input
direct drive by setting parameter 34 to 02.
The firing rate of the boiler is controlled by an
external 0 to 10 VDC signal. At a voltage greater
than 0.5 VDC the boiler turns on and runs at low fire
until 1.8 VDC is reached. The firing rate increases
linearly with voltage until high fire is reached at 10
VDC. The boiler setpoint Parameter 4 remains active
to shut down the boiler when the temperature in the
boiler exceeds this value plus the high temp
differential. These voltage levels, as explained
above, are all “non-adjustable”.
3.12.2 Gas Pressure Adjustment
Note: Adjustments shall only be performed by
service representative specifically trained and
certified to perform maintenance on the
Patterson-Kelley MACH Series boiler.
See rating plate for the minimum and maximum gas
pressure of the boiler. Each boiler is furnished with a
manual shut-off valve which has an integrated test
port.