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Applications & Modes
The VERSA IC
Control system is designed for a wide
®
range of applications. The installer/design engineer
should refer to the following drawings for configura-
tions currently supported by the VERSA IC
system to determine which most closely resembles the
intended/installed system configuration. Refer to the
section(s) of this manual for instructions outlining the
piping layout, sensor locations and settings for best
operation of the specific configuration shown.
Hot water heating systems all have unique levels of
operating diversity that must be accounted for in the
system design. The system should always include
adequate system flow in excess of the connected boil-
er flow for proper operation. Where the system flow
may drop below the connected boiler flow, a
buffer/decoupler may be needed. Failure to design for
adequate flow (i.e. bypasses, 3-way control valves,
flow limiting balance devices, buffer tanks, etc.) will
result in boiler short cycling and may reduce boiler life.
Always contact your local Raypak representative for
system design assistance to avoid these issues.
MODE 1 Hydronic Systems
without Indirect DHW
This section covers single- or multiple-boiler installa-
tions used for individual hydronic heating systems
without indirect DHW. The following diagrams will
show single-boiler systems with and without CWP. The
CWP diagrams will show an individual 3-way valve at
the boiler (MIX Type = BOIL). The following piping con-
figurations can be used as fixed set-point or set up to
work in conjunction with an Outdoor Air Reset Sensor
(S4) to adjust the target water temperature as the out-
door air temperature changes.
MODE 1 Single
Primary/secondary piping is the only method support-
ed by Raypak to ensure proper boiler and system
functionality while achieving maximum system efficien-
cy.
CAUTION: Continous pumping through the unit is
not supported and may cause a non-warranty failure.
The boiler firing rate will be controlled by the System
Sensor (S3). See System Sensor Installation on
page 9. The VERSA IC
(Differential Temperature) control and will cycle the
burner if the Max Delta T is exceeded between Boiler
Outlet Sensor (S1) and Boiler Inlet Sensor (S2).
In order to enable MIX settings, VERSA
Control
®
will provide Max Delta T
®
DIP #3 must
®
be set to ON position. Raypak's Cold Water protection
system utilizes a proportional 3-way valve to bypass
water from the boiler outlet to the inlet during opera-
tion, when the system return water temperature is
below the minimum acceptable level as defined in the
Installation and Operating manual for the product
being installed.
The Boiler Pump (P1) runs during any call for burner
operation and is delayed "off" as user-defined in the
BOILER menu after the burner has shut down. The
System Pump (P2) runs whenever the system is
enabled for heating and the outdoor air temperature is
lower than the WWSD temperature setting (if utilized).
The System Pump is delayed "off" as user-defined in
the SETUP menu. MODE 1 is used for this configura-
tion. See SETUP menu items in Table B page 15. This
configuration supports BMS 0-10 VDC input for tem-
perature or rate control and can be configured for
connectivity to BMS via the onboard Modbus port cov-
ered later in this manual.
Ensure DIP switch #1 and 2 on the VERSA Control
Board are in the ON position to make programming
changes. Prior to setting any DIP switches, the heater
must be turned off.
NOTE: 0-10VDC firing rate control ignores all
functions except Limit/and Safety Switches, Max
Delta T and CWP.
MODE 1 Cascade
The following diagrams will show cascade systems (up
to 4 boilers maximum) with and without CWP. The
CWP diagrams will show either an individual 3-way
valve at the boiler (MIX Type = BOIL) or a single 3-way
valve providing CWP to all connected boilers within the
cascade (MIX Type = PLNT). The following piping con-
figurations can be used as fixed set-point or set up to
work in conjunction with an Outdoor Air Reset Sensor
connected to the Master unit (S4a) to adjust the target
water temperature as the outdoor air temperature
changes.
Reverse/return piping is shown and is recommended
to ensure balanced flow through each of the connect-
ed boilers. Primary/secondary piping is the only
method supported by Raypak to ensure proper boiler
and system functionality while achieving maximum
system efficiency.
NOTE: "a" designation represents connection is at
Master boiler "A"
11
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