17
Installation
CNA-Series Tankless Heater
Keltech •
215-1814 Rev. C; ECN 150010
7/13/2015
Special Installation and Operating Instructions
Tankless Water Heaters With Optional Class I Division 2 Purge EXP2CFPM Option
General Information
All Keltech Tankless Water Heaters with a model number suffix of – EXP2CFPM have been fitted with a Z purge
system to pressurize the enclosure suitable for use in Class I Division 2 Hazardous Locations .
A Continuous Flow (Model CF) Mini-Z Pressurizing System has been fitted to the inside of the enclosure .
Outlet
18"
(458mm)
Max
Explosion proof
sealing fitting
supplied by others
Purge System
Relief Valve
Conduit Hub
Class 1 Div . 2
supplied by others
Inlet
1
1
2
3
4
5
6
3
5
6
Suggested region for power
entrance at right/bottom of
enclosure . Entrance hole and
components to be provided by
installer .
All plumbing fittings are 1-1/4" NPT
female threaded .
Purge Control Panel
Class 1 Division 2
All installation egress from
panel must be sealed (electrical
conduit) for proper explosion proof
installation .
Spark arrestor with calibration
orifice is located in the bottom of the
enclosure .
Purge gas/compressed air inlet
fitting here .
EXP2CFPM Installation Notes
1 . Any tubing, conduit or fittings connected to the Pressurized Enclosure (PE) must conform to local codes for
flammability ratings .
2 . All egress into PE must be plugged and properly sealed to minimize leakage of purge air . Use hazardous
location sealing fittings suitable for Class I locations within 18" of enclosure .
3 . The EXP2CFPM purge system option is a continuous flow purge system mounted inside the cabinet enclosure
and calibrated to flow at 0 .9 SCFM . To minimize waste, plug and seal all openings and conduit .
4 . The system is designed for use primarily with compressed air . The source of the compressed air must be
from a non-classified area (see Purge Gas Supply Notes) . Purge air must be clean, dry and free of flammable
gases . When inert compressed gases are used (Nitrogen, for example) the installer and facility manager must
take suitable precautions on-site so that buildup of the inert gas does not present a health hazard . Where risk
of asphyxiation exists, a warning label must be fitted to the Pressurized Enclosure (PE) .
5 . Adjustment of Purge System is not necessary . System is fully calibrated .
6 . Connect to Purge System where indicated above . Connection port is 1/4" NPT female . Supply pressure must be
regulated to 60–115 PSI .