RECO HX2 Series, Nstallation, Operation And Maintenance Manual

Page: 11 / 40

S
ECTION
2 - I
NSTALLATION
HX2 S
ERIES
2 - 3
2.3.6 An electrically operated, fast-acting V-ball control valve is used to modulate flow of
heating medium to the unit. It has a 100:1 rangeability which gives excellent control
at all flow rates. Capacitors integrated into the actuator housing close the valve in
the event of loss of power.
2.3.7 The steam trap and strainer are a float and thermostatic (f & t) type steam trap and
“Y” type strainer. These components are suppl ied loose for connection at the steam
(condensate) outlet of the heating tube bundle.
2.3.8 The insulation jacket is a flexible, Velcro-attached design specific to the unit it
insulates. All cut outs and openings for piping and instrumentation are provided for
easy installation without the need for field modification.
2.3.9 The tube bundle is provided pre-assembled into the heating tank, with all piping and
controls installed and tested, ready for start-up and operation.
2.3.10 The Control Master control panel is a complete, pre-assembled and pre-wired unit
with a programmable automation controller (PAC) and easy to navigate LCD panel for
local monitoring and set point adjustment.
2.4 Factory Pre-Sets
All temperature settings for the unit are factory set for the specified outlet temperature
requirements. This is typically 120
 F or 140  F.
2.4.1 The temperature pre-sets start with the RTD sensor and PID control loop tied to the
control panel PAC. It is set to the specified outlet water temperature, and modulates
the control valve position to maintain the inflow of steam corresponding to the demand
for hot water. Upon reaching the desired water outlet temperature, the control valve
will back off to the point it may fully close. Outlet water temperature is controlled to
+/- 4
 F.
2.4.2 The high temperature alarm is set to 10  F above the outlet temperature setting. Upon
reaching this setting the control panel LCD display will blink and send an alarm signal
to the BAS (if so wired). Upon returning below this high temperature setting, the
system will automatically come out of alarm mode and reset itself without the need for
a manual reset.
2.4.3 In addition to the RTD sensor and PID control loop, a separate high temperature limit
switch is provided. This is pre-set to 10
 F above the high temperature alarm setting
(which is 20  F above the outlet water temperature setting). In the event the high
temperature limit switch is tripped, it will cut power to the control panel. This will de-
energize the steam inlet control valve, causing it to fail closed and cut off any further
supply of steam to the unit, and energize the tank-mounted solenoid valve, causing it
to open and relive any pressure in the tank.
2.4.4 As a third safety feature, a factory pre-set pressure / temperature relief valve mounted
near the tank outlet will open upon reaching its high pressure or temperature setting,
relieving the contents of the tank until the internal pressure in the tank falls below the
valve settings. These settings are typically 150 PSIG and 210
 F, respectively.