CCI Thermal Technologies CWCB - Packaged Circulation Heater - Manuel (Page 2)

2.7.4 a pressure relief valve is a safety feature which is intended to
open when the system malfunctions or is improperly operated or
maintained. unites equipped with a pressure relief valve should
be fitted with piping to direct the discharge down and away from
personnel or equipment. neVer install a sHut oFF ValVe
on eitHer siDe oF a Pressure relieF ValVe.
2.7.5 optional expansion tank (for closed loop systems) is mounted in
the outlet piping.
2.7.6 A 1½" NPT drain plug is fitted at the bottom of the heater. We
recommend use of a drain valve to simplify clean-out of sludge
which may accumulate in the vessel. sludge build-up can cause
heating element failure.
2.7.7 For flow rates greater than 50 gpm, to reduce tank erosion, a
bypass loop with regulating valve is recommended.
2.7.8 Closed loop systems require an air bleed valve, preferably
installed at the highest point in the piping loop.
3.0 START UP AND OPERATION
3.1 the CW heater is designed to heat water in a non-hazardous
environment. in some closed loop systems chemically stabilized
ethylene glycol may be added to the water for freeze protection or
toe elevate the boiling point. if you are unsure as to suitability of
glycol to your heating loop contact the factory.
3.2 Check the electrical system for the loose connections and tighten
if required.
3.3 after all piping is installed turn the thermostat to its lowest setting
and operate the circulating pump for up to 1/2 hour to check for
leaks and to remove air pockets. in closed loop systems use the
air bleed valve to remove entrapped air. an air lock in the heater
vessel could cause the heaters to run dry and fail prematurely.
3.4 set the thermostat to the desired temperature. the temperature
rise through the unit will depend on the flow rate and the heater
kilowatt (Kw) rating.
For water: GPM
imp
=
example: For a 30 Kw heater and a 10 °F temperature rise the
flow required in imperial gallons per minute is:
GPM
imp
= = 17
adjust the thermostat differential to give the desired cycling rate.
it is best to use the maximum acceptable differential so as to
minimize cycling and prolong component service life. However, if
the system requires close control a narrow differential setting will
be necessary.
3.5 For systems using a bypass loop, open the bypass valve to
reduce the load on the pump but not enough to cause the limit
thermostat to open. For pool heating, the ideal bypass opening
will result in water leaving the heater at not more than 90 °F.
5.69 Kw
temp. rise (°F)
(5.69)(30)
10
3.6 the built-in temperature high limit is factory set at 180°F (82°C).
this control works best when it is set about 40°F (22°C) above
the water outlet temperature. to adjust the limit control setting
remove the small panel on the limit control to access the
adjustment screw. under normal operation the heater should not
cycle on the limit control.
3.7 if the limit trips it must be manually reset before the heater will
operate. Prior to reset, the condition(s) which caused the trip shall
be corrected.
4.0 MAINTENANCE
4.1 service to the unit shall only be done when the power is
disconnected at the mains.
4.2 After the first few days of operation, and periodically thereafter,
inspect for piping leaks and loose electrical connections.
4.3 the CWCB-XXX-2 unit, because it is used in an open loop water
heating system, may be subject to sludge build-up if the water is
hard and untreated. this unit must be drained at regular intervals
(depending on water conditions and operating time to remove
sludge. Once a year a flange heater must be removed and the
vessel inspected and cleaned as required. local conditions may
cause the inspection time to vary.