Raypak 2503, Инструкция по установке и эксплуатации

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service life of the appliance and the vent system. A
bypass allows part of the heater discharge water to be
mixed with the cooler water returning to the heater
inlet to increase the heater inlet temperature above
120°F (49°C). This precautionary measure should pre-
vent the products of combustion from condensing
beyond the ability of the condensate management sys-
tem employed in this heater in most installations.
Warranty claims will be denied for damage or fail-
ures caused by condensation.
Cold Water Starts
Cold water starts, where the inlet water temperature
remains below 120°F (49°C) must have cold water
start protection . Known protection methods consist
of mixing heated outlet water with the inlet water using
a bypass to raise the inlet to 120°F (49°C) or higher.
Once the system is heated up and has return water
temperatures of 120°F (49°C) or higher, the mixing of
outlet water with inlet water is no longer needed and
the bypass can be shut off. If the bypass is not shut off
as the system heats up, the outlet temperature may
continue to climb and trip the high limit, thereby shut-
ting down the heater. Thus an automatic valve system,
such as a three-way proportional valve to control the
bypass, should be used.
Cold Water Run
Cold water run differs from cold water start in that the
system water entering the heater remains below
120°F (49°C) continuously. Typically, this is the case in
water source heat pump applications as well as some
others. If the system water is kept in a narrow temper-
ature range of no more than 10°F (5°C), a permanent
manual bypass can be employed and manually adjust-
ed to achieve an inlet temperature of 120°F (49°C) or
higher as adjusted at the minimum temperature in this
narrow temperature range (i.e. Range 75°F to 85°F,
adjust bypass with temperature at 75°F (24°C)) so that
when temperature is 85°F (29°C), minimum inlet tem-
perature would be 130°F (54°C). An injector pump
arrangement may also be utilized to keep the heater
loop at or above 120°F (49°C). An injector pump
approach has the added value of being able to adjust
to changes in the system water coming back to the
heater.
Hydronic Heating
Pump Selection
In order to ensure proper performance of your heater
system, you must install a correctly-sized pump. Ray-
pak requires designing for a ∆T within the range of
16°F to 39°F (9°C to 22°C). See Table F for accept-
able flow rates for each model (∆T is the temperature
difference between the inlet and outlet water when the
heater is firing at full rate).
*
Fig. 10: Cold Water Start
*
Fig. 11: Cold Water Run
*Maximum 4 times the pipe diameter or 12”, whichever is less.
*Maximum 4 times the pipe diameter or 12”, whichever is less.