16
For detailed information on the Versa IC™ control sys-
tem, see Catalog 5000.72. This manual can be found
in the document library at www.raypak.com.
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.
Fig. 14: MODE 1 - Boiler Cascade with
Primary/Secondary Piping
Fig. 13: MODE 1 - Single Boiler with
Primary/Secondary Piping
Fig. 12: Air-Separation/Expansion Tank
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 MVB 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.
piped in parallel with the heater with appropriate
valves to pre-vent 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.
Air-Separation/Expansion Tank
All heaters should be equipped with a properly sized
expansion tank and air separator fitting as shown in
Fig. 12 .
Summary of Contents for MVB 504A
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