Form: 2435
Revision: 9
Free Flex Installation and Operation Manual
Date: 9-1-2017
Bryan Steam LLC, 783 N Chili Ave, Peru IN 46970
Web:
www.
bryanboilers
.com
Phone:
765-473-6651
Fax:
765-473-3074
Email:
44
5.6
Safety and Operating Controls
All of the safety control devices listed in Table 16 are logically linked to the Concert Boiler Control
that supervises the sequence of operation of the boiler for safe and efficient operation. It does so by
ensuring proper light off and firing of the main burner and if need be, will immediately cut-off gas
supply to the main burner when gas pressure, water temperature, water flow or another critical
attribute is outside of the operational settings. It also varies the combustion rate in real time to meet
the desired load of the system.
WARNING
Do not install, operate, service or repair any components of this equipment unless you are
qualified and fully understand all requirements and procedures. Trained personnel should
refer to those who have completed Bryan Steam Service School training specific to this
product.
Table 16: Safety and Operating Controls
Component
Function
Power
Switch
If this switch is in the off position, power is interrupted to the control circuit of the boiler,
which prevents the boiler from operating. If the switch is in the on position, power is
supplied to the control circuit.
Automatic
Reset
Operating
Aquastat
If the boiler water temperature exceeds the adjustable set point, power is interrupted to the
control circuit of the boiler, which prevents the boiler from operating. When the boiler water
temperature drops below the set point minus the adjustable differential setting, power is again
supplied to the control circuit.
Manual
Reset High
Limit
Aquastat
If the boiler water temperature exceeds the adjustable set point, power is interrupted to the
control circuit of the boiler, which prevents the boiler from operating. Power is interrupted
until the control is manually reset pressing the control’s reset button. When the button is
pressed, power will again be supplied to the control circuit, assuming that the boiler water
temperature has dropped below the setpoint minus the differential setting.
Water Flow
Switch
If the water flow through the boiler drops below the fixed flow rate required to move the
control’s paddle enough to close the control’s contacts, power is interrupted to the control
circuit, which prevents the boiler from operating. When the water flow rate increased, the
paddle closes the control’s contacts and power is supplied to the control circuit.
Pressure /
Safety
Relief
Valve
If the pressure inside the boiler exceeds the fixed set point, the valve opens mechanically and
discharges water. The valve remains open until the pressure inside the boiler drops below the
set point.
High and
Low Gas
Pressure
Switches
If the gas pressure reaches a point above or below the adjustable set point, the contacts of
the switch open and power is interrupted to the control circuit that prevents the boiler from
operating. Power is interrupted until gas pressure is between the high and low gas pressure
set points and the control is manually reset moving the switch to the reset position. The
switches will not reset until the gas pressure is within the set point parameters.
Minimum
Air
Pressure
Switch
If the differential air pressure drops below the fixed set point, the contacts of the switch open
and power is interrupted to the control circuit, which prevents the boiler from operating.
Power is interrupted until air flow/pressure increases so that contacts close.
Maximum
Air
Pressure
Switch
If the differential air pressure exceeds the fixed set point, the contacts of the switch open and
power is interrupted to the control circuit, which prevents the boiler from operating. Power
is interrupted until air flow/pressure decreases below the setting so that the contacts close.
