Optional Equipment - Heat Transfer MODCON VWH 300 LP Installation & Maintenance

PART 2: BEFORE YOU START
The cascade system is capable of connecting
up to eight boilers together in such a way that
they function as one boiler system. This
allows for greater turn down ratios and
provides systematic control of the multiple
boilers in an installation to minimize
downtime and maximize efficiency.
The cascade system works by establishing
one boiler as the master and the other
connected boilers as followers.
4. System Display and Operation Led light
Indicators – The display allows the user to
change the system parameters and monitor
the system outputs. Led light indicators
monitor system operation .
5. Gas Valve – The gas valve senses suction
from the blower allowing gas to flow only if
the gas valve is powered and combustion air
is flowing.
6. Swirl Plate or Venturi – Controls the air and
gas flow into the burner.
7. Burner – Constructed of high grade stainless
steel, the burner uses premixed air gas and
provides a wide range of firing rates.
8. Spark Ignition – The burner is ignited by
applying a high voltage through the system
spark electrode. This causes the spark from
the electrode to ignite the mixed gas off of
the burner.
9. Supply Water Temperature Sensor – This
sensor monitors the boiler outlet water
temperature (System Supply). The control
adjusts the boiler firing rate so the supply
temperature will match the boiler set point.
10. Return Water Temperature Sensor – This
sensor monitors the boiler return water
temperature (System Return). The control
adjusts the boiler firing rate depending on
how close the return water temperature is to
the supply water temperature.
11. Temperature and Pressure Gauge – Allows
the user to monitor the system temperature
and pressure.
12. Electrical field connections with terminal
strips – The electrical cover allows easy
access to the line voltage and low voltage
terminals strips which are clearly marked to
facilitate wiring of the boiler.
13. Condensation Collection System – This boiler
GAS-FIRED HOT WATER SUPPLY BOILER
(CONT'D)
is a high efficiency appliance, therefore the
boiler will produce condensate. The collection
system has a float switch to monitor the
condensate level to prevent condensate from
backing up into the combustion system. There
is a built in trap inside the collection system to
seal the combustion system from the
connected drain. The condensate should be
neutralized to avoid damage to the drainage
system or piping.
14. Flow Protection – The supplied flow switch is
designed to protect the boiler in the event of
low flow conditions. The boiler control will
also monitor the flow through the heat
exchanger by monitoring the return and
supply sensor and will shut down the burner
before overheating occurs.
15. System Pipe Sensor – The supplied System
pipe Sensor is designed to be used in a
Cascade System when the sensor is placed
on the supply line of multiple boilers that feed
the storage tank. This will control the
temperature and modulate the firing rate of
the connected boilers.
16. Indirect Tank Sensor (optional) – Used to
monitor tanks l temperature.
C. OPTIONAL EQUIPMENT
Below is the list of optional equipment available
for Mod Con Boiler.
• Indirect Tank Sensor (Part # 7250P-325)
• 4" Stainless Steel Outside Termination Vent
Kit (V2000)
• 6" Stainless Steel Outside Termination Vent
Kit (V3000)
• High and Low Gas Pressure Switch Kit with
Manual Reset (Part # 7350P-600)
• U.L. 353 Compliant Low Water Cut-Off
Interface Kit with Manual Reset (Part # 7350P-
601)
• Alarm System (Part # 7350P-602) (to monitor
any failure)
• Stacking Kit (Part # 7350P-603)
• PC Connection Kit (Part # 7250P-320)
• Boiler Caster Kit (Part # 7350P-604)
• Mod Con Condensate Neutralizer (Part #
7350P-611)
These additional options may be purchased
through your HTP Distributor.
Boiler Manual
8