Venting - General - Raypak XTherm 1005A Installation And Operation Manual

FIELD
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Figure 33. Cascade Follower
3.13.8. Modbus BMS Communication
The VERSA IC control is equipped as standard with
a communications port for connectivity to building
automation via Modbus protocol. Refer to the VERSA IC
manual (5000.72) for further information.
3.13.9. Alarm Connection
An alarm annunciator or light may be connected to the
alarm contacts on the field wiring terminal strip. The
Alarm Contacts are 3A rated dry contacts on a normally-
open relay that close during fault or lockout conditions,
and the maximum voltage across the contacts is 30 VAC
or 30 VDC. See Figure 29.
In a cascade system with an alarm condition at one or
more units, all alarm contacts within the cascade will be
energized indicating a fault condition.

3.14. Venting - General

CAUTION: Proper installation of flue venting is critical
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for the safe and efficient operation of the heater.
NOTE: Raypak strongly recommends installing the vent
system before water piping. This will ensure that the
venting system and associated components will fit into
the allotted space for proper operation.
3.14.1. Appliance Categories
Heaters are divided into four categories based on the
pressure produced in the exhaust and the likelihood of
condensate production in the vent.
Category I – A heater which operates with a non-positive
vent static pressure and with a vent gas temperature that
avoids excessive condensate production in the vent.
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Category II – A heater which operates with a non-positive
vent static pressure and with a vent gas temperature that
may cause excessive condensate production in the vent.
Category III – A heater which operates with a positive
FACTORY
vent pressure and with a vent gas temperature that avoids
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excessive condensate production in the vent.
Category IV – A heater which operates with a positive
vent pressure and with a vent gas temperature that may
cause excessive condensate production in the vent.
See Table O for appliance category requirements.
NOTE:
categorization, see appropriate ANSI Z21 Standard
and the NFGC (U.S.), or B149 (Canada), or applicable
provisions of local building codes.
WARNING: Mixing of different manufacturer's venting
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material is not permitted as this may create an unsafe
condition.
CAUTION: Condensate drains for the vent piping are
required for installations of the XTherm. Follow vent
manufacturer instructions for installation and location of
condensate drains in the vent. Condensate drain must use
a trap and the trap must be primed with water to prevent
flue gas leakage and must be routed to an appropriate
container for treatment before disposal, as required by
local codes.
WARNING: Contact the manufacturer of the vent
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material if there is any question about the appliance
categorization and suitability of a vent material for
application on a Category IV vent system. Using improper
venting materials can result in personal injury, death or
property damage.
WARNING: Condensate is acidic and highly corrosive.
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Centrotherm™ polypropylene vent material is approved
to be used on XTherm products. A field-installed vent
adapter supplied by Raypak (option D-33) must be used to
ensure a proper seal of the flue and condensate. The D-33
kit includes a required vent temperature limit.
3.14.2. Support of Vent Stack
The weight of the vent stack or chimney must not rest on
the heater vent connection. Support must be provided
in compliance with applicable codes. The vent should
also be installed to maintain proper clearances from
combustible materials. Use insulated vent pipe spacers
where the vent passes through combustible roofs and
walls.
For additional information on appliance