Feedwater Regulator
Raypak recommends that a feedwater regulator be in-
stalled and set at 12 psi minimum pressure at the
highest point of the system. Install a check valve or
back flow device upstream of the regulator, with a
manual shut-off valve as required by local codes.
Piping
All high points should be vented. A heater installed
above radiation level must be provided with a low wa-
ter cut-off device (sales order option F-10). This
heater, when used in connection with a refrigeration
system, must be installed so that the chilled medium is
piped in parallel with the heater with appropriate
valves to prevent the chilled medium from entering the
heater.
The piping system of a hot water heater connected to
heating coils located in air handling units where they
may be exposed to circulating refrigerated air, must be
equipped with flow control valves or other automatic
means to prevent gravity circulation of the heater
water during the cooling cycle. It is highly recommend-
ed that the piping be insulated.
14
Table H: Heater Rates of Flow and Pressure Drops
Notes: Basis for minimum flow is ∆T . Basis for maximum flow is gpm.
Model
No.
20°F ∆T
30°F ∆T
35°F ∆T
Min. Flow
Max. Flow
gpm ∆P (ft) gpm ∆P (ft) gpm ∆P (ft) gpm ∆P (ft)
∆T
gpm ∆P (ft) ∆T
H7-300A
28
17
19
8
16
6
14
5
39
36
28
16
H7-400A
38
18
25
7
21
5
19
4
39
47
29
16
H7-500A
47
16
31
7
27
5
24
4
39
56
23
17
H7-700A
66
30
44
13
38
9
34
7
39
70
34
19
H7-850A
80
40
53
17
46
12
41
10
39
80
40
20
Fig. 6: Air-Separation/Expansion Tank
Air-Separation/Expansion Tank
All heaters should be equipped with a properly sized
expansion tank and air separator fitting as shown in
Fig. 6 above.
Three-Way Valves
Three-way valves intended to regulate system water
temperatures by reducing flow in the boiler should not
be used. Raypak heaters are high-recovery, low-mass
heaters which are not subject to thermal shock.
Applications & Modes
The VERSA IC Control system is designed for a wide
range of applications. The installer/design engineer
should refer to the following Modes to determine which
best fits the intended application and functionality for
the unit being installed.
Type H models of XFyre have three modes available
to them to address the various applications the units
can be applied to. Type WH units will only have the
WH configuration available to them for use with
potable water applications when directly connected to
a hot water storage tank.
Mode 1 (Type H Units Only)
This mode selection is for hydronic heating systems
with single or multiple boilers (Maximum 4 boilers) in
primary/secondary piping configuration with or without
Outdoor Air Reset (S4). The system temperature is
controlled by the System sensor (S3). The Boiler
Pump (P1) runs during any call for heat. The System
Pump (P2) runs whenever the system is enabled for
heating and the outdoor air temperature is lower than
the warm weather shut down (WWSD) temperature
setting (if utilized). The Boiler Pump and System Pump
are delayed “off” as user defined in the
ADJUST
menu.
Summary of Contents for 300A
Page 44: ...WIRING DIAGRAM 44...
