Keltech CNA-36 User manual

729 S. Grove St., Delton, MI 49046
TEL: [phone] • 800-999-4320 FAX: [phone]
[email protected] • www.keltech-inc.com
Installation
215-1814 Rev. C; ECN 150010
© 2015 Keltech
Page 1 of 20 7/13/2015
CNA-Series
Tankless Heater Models
CNA-36
CNA-54
CNA-63
CNA-72
CNA-108
CNA-126
CNA-144
CNAR-108
CNAR-126
CNAR-144
Voltage options for models:
600V 3-phase
480V 3-phase
415V 3-phase
400V 3-phase
380V 3-phase
Table of Contents
Pre-Installation Information .........................2–3
Storage Instructions .................................4
Mounting Heater....................................5
Plumbing Installation ................................6
Electric Installation ..................................7
Start Up Check List .................................8
Start Up ..........................................9
Digital Controller Operation ..........................10
Operational Tests ...............................11–12
Product Options ...................................13
Maintenance......................................14
Troubleshooting ................................15–16
Special Installation & Operating Instructions ..........17–20

2
CNA-Series Tankless Heater Installation
7/13/2015 Keltech • 215-1814 Rev. C; ECN 150010
DANGER
Tipover hazard. System can crush you resulting in serious injury or death. Read and follow precautions in
this installation manual for instructions on how to safely transport and mount. Do not transport with the
heater in the vertical position. This heater is top heavy and should not be placed in the vertical position until
the site is prepared to anchor the legs to the floor.
WARNING
Read this manual BEFORE using this equipment. Failure to read and follow all safety and user information
could result in death, serious personal injury, minor burns, property damage, or damage to the equipment.
Keep this Manual for future reference. Failure to comply with proper installation and maintenance instructions
could contribute to the heater’s failure.
A qualified plumber or electrician should install and service this system. Install system according to these
instructions and in compliance with national and local codes.
ASSE standard 1016, 1069 or 1070 listed devices should be used at fixtures to prevent possible injury. Severe
bodily injury including scalding, chilling, and/or death may result depending upon system water pressure
changes and/or supply water temperature changes.
For safe operation of the heater, observe all warning labels as indicated.
Water heater system under pressure. Do not open enclosure while in operation.
These heaters should never be used to provide “anti-scald” or “anti-chill” service.
Hazardous voltage inside enclosure may result in serious burns or death. Disconnect power supply before
performing any work in the enclosure.
Failure to ground this system may result in death or serious injury.
Make sure that all water supply lines have been flushed and then completely turned off before beginning
installation. Debris in supply lines can cause valves to malfunction.
CAUTION
Hot pipes! Do not touch. May cause minor burns.
NOTICE
These heaters do not provide protection from supply or outlet pipe freezing.
Consult local building and plumbing codes prior to installation. Should these codes differ from the information
in the Manual, follow the local codes. Inquire with governing authorities for additional local requirements.
Regular checking and cleaning of the heater’s internal components and check stops is necessary for maximum
life and proper product function. Periodic inspection and yearly maintenance by a licensed contractor is
required. Corrosive water conditions, and/or unauthorized adjustments or repairs could render the heater
ineffective for its intended service. Frequency of cleaning and inspection depends upon local water
conditions. For heaters with adjustable output temperatures, check and adjust as needed at initial installation
and on a quarterly basis.
IMPORTANT
Read this entire installation manual to ensure proper installation. When finished with the installation, file this
manual with the owner or maintenance department. Compliance and conformity to local codes and ordinances
is the responsibility of the installer. Product warranties may be found under “Products” on our Web site at
www.keltech-inc.com.
Separate parts from packaging and make sure all parts are accounted for before discarding any packaging
material. If any parts are missing, do not begin installation until you obtain the missing parts.
A qualified plumber or electrician should install and service this system. Install system according to these
instructions and in compliance with national and local codes.

3
Installation CNA-Series Tankless Heater
Keltech • 215-1814 Rev. C; ECN 150010 7/13/2015
Pre-Installation Information
General Information
The Keltech Tankless Water Heater provides instant and precise temperature-controlled hot water. To insure proper
performance, install the heater according to the following installation instructions and in compliance with applicable
national and local codes.
Keltech can supply heaters for most commercial and industrial hot water applications. Flow rates and temperature
figures are important for proper sizing. If needed to meet certain temperature demands, flow control devices
are readily available. See Maximum Temperature Rise Specifications chart. Contact KELTECH, INC. for further
information on available flow control devices.
Operation and Setup
CNA-Series heaters supply an unlimited amount of hot water with specific flow and temperature rise capabilities.
These heaters are energy efficient, reliable, and provide optimum performance in the most demanding applications.
Application Specific Requirements
The CNA-Series can be used in many different applications that require custom tuning for specific applications to
maximize performance of the heater.
For use in a recirculation loop, the incoming loop temperature should not exceed 140°F (60°C) to ensure water
cooling of the solid state relay.
For applications utilizing quick close valves or solenoid valves, it is important to install a hammer arrestor or surge
tank close to the point of use to absorb pressure spikes.
ASME CERTIFICATION: Please verify if your State Boiler Code requires ASME Certification and that you have the
proper heater to meet your code requirements prior to installation.
Installation Considerations
Maximum operating pressure: 160psi.
Minimum flow activation: 1.5 gpm
SCCR Rating
Keltech Electric Tankless Water Heaters are certified by ETL to UL499, UL50E and CSA22.2 No 88. It is designed to
comply with UL508A.
The SCCR load rating is marked on the enclosure per UL508A requirements for Water Heaters controlling a resistive
heating element load.
WARNING For safe operation of the heater, observe all the warning labels as indicated.

4
CNA-Series Tankless Heater Installation
7/13/2015 Keltech • 215-1814 Rev. C; ECN 150010
Storage Instructions
NOTICE! Keep Keltech Electric Tankless Water Heaters stored in original packaging until installation.
Recommended storage criteria:
Store Keltech Electric Tankless Water Heaters where temperatures exceed 35ºF (2º C) at all times.
Indoor storage is recommended.
Minimize excessive on-site transport to reduce risk of shock and impact damage.
Alternate storage:
If in the original crate, Keltech Electric Tankless Water Heaters will withstand outside storage for approximately 1
month in most climates. Crate may not be capable of protecting the heater if left outside longer than this time frame.
If the Keltech Electric Tankless Water Heater is stored in an outdoor environment, care should be taken to protect the
heaters from:
• Rain or other falling precipitation via tarp or other waterproof media.
• Runoff and accumulation of groundwater from any source that may exceed 1 inch.
NOTICE! For heaters with ENHT freeze protection option: If the heater is stored where the temperature
could fall below 45°F(7°C), the heater must be powered immediately after hydro testing to insure
internal freeze protection components are activated. Once the heater is installed and the on-site
plumbing has been hydro tested, the power supply must remain constant until the risk of freeze is
eliminated. If this is not possible, do not allow the heater to remain full of water. The heater must
be drained. Freezing of the heater can cause serious damage. Follow notes in Start Up Check List
section following an electrical lockout/tagout procedure.
Packaging
Crates are constructed from 3/4" OSB.
Crate dimensions approx: 82" x 48" x 24" (2083mm x 1219mm x 610mm)
Crates should not be stacked more than 2 high.
All crates must be stacked evenly and horizontally.
Safety issues related to packaging:
• Product should be transported with the care associated to packages labeled “FRAGILE” even if packaging is not
marked accordingly.
• Standard safety procedures for forklift transport and large items less than 1000lbs should be followed at all times.
• When stored, crate must be supported in entirety of its length and width.

5
Installation CNA-Series Tankless Heater
Keltech • 215-1814 Rev. C; ECN 150010 7/13/2015
Mounting Heater
1
WARNING HIGH VOLTAGE SHOCK. Disconnect power supply before performing any work inside
the heater enclosure.
For best results, install heater as close as possible to the point of use.
Installation is to be performed by licensed trades people.
Long pipe runs are not recommended. A heat loss of 1°F for every 10ft (3 meters) of uninsulated
pipe can occur.
When determining a mounting location, give consideration to the location of the main electrical
panel and ensure accessibility of the enclosure door and other plumbing for service/maintenance.
36" minimum in front of the cabinet enclosure and 48" minimum above the cabinet enclosure are
required.
Bottom View - Leg Mounting Holes
30" (762mm)
12"
(305mm)
2"
(51mm)
4"
(102mm)
8"
(204mm)
6-7/8"
(175mm)
16-1/4"
(413mm)
3-7/8"
(99mm)
3/4" x 7/16" Slot
(6) Places
If heater is installed where freezing can occur, specify Keltech's ENHT Freeze Protection option. Keltech's ENHT
option must be purchased at the time of order. Do not install in areas where freezing can occur without the ENHT
option listed in the model number.
A
Set the heater in a vertical, upright
position with the water outlet located
at top. Use the floor mounting template
on the side of the crate to help with
alignment of the leg mounting.
BSecure heater by bolting each leg to the
floor using 3/8” anchor bolts.
C
Install the pressure and temperature relief
valve on hot water outlet immediately
following the union.
NOTICE! Valve must empty into a
drain.
Rectangle outline on template is not actual size of
heater.
Template may require cutting to fit into tight areas.
Holes are for alignment purposes and may not
represent actual drill size for mounting hardware.

6
CNA-Series Tankless Heater Installation
7/13/2015 Keltech • 215-1814 Rev. C; ECN 150010
Plumbing Installation
2
B
Install one union on the water inlet side of the
heater and another union upstream of the 100
Mesh (150 micron) y-strainer.
Install one union on the water outlet side of the
heater and another after the P & T Relief Valve.
Install the pressure relief valve (150 psi) and outlet
plumbing of heater per code requirements and
route relief valve discharge to drain. Make sure no
shutoff valve is between the relief valve discharge
and the drain. Install hammer arrestor. Ensure
plumbing is secure and not subject to vibrations.
CUse 1-1/4" hard copper tubing or pipe as needed.
AInstall shutoff valve above (upstream of)
the heater inlet.
CAUTION To avoid damage to the electronics
or internal wiring, do not perform
any brazing or sweat soldering
inside the enclosure.
NOTICE! Failure to install proper filtration may
result in a flow sensor malfunction.
NOTICE! To avoid water damage, install a drain
pipe from the pressure relief valve to an
unrestricted drain.
If end use fixture is not at the highest point in
the plumbing loop, then an automatic air vent
valve must be added at the highest point in the
system or at any drop to eliminate trapped air.
Components Needed:
• (4) Union 1-1/4"
• Shutoff Valve
• Pressure and Temperature Relief Valve (150 psi)
• Y-Strainer (100 mesh) or Inline Filter (150 microns)
• (2) Gate or Ball Type Valves
• Drain pipe
• Water hammer arrestor (recommended)
• Elbows, nipples and fittings as needed
B
C
A
31-1/2"
(800mm)
23-1/2" (597mm)
5-1/2" (140mm)
15-1/4"
(387mm)
3-3/4"
(95mm)
6" (152mm)
30"
(762mm)
12"
(305mm)
1-1/4" Female NPT
Outlet
1-1/4" NPT
Female
Inlet
Suggested Location For
Power Entrance. Holes
Provided By Installer.
Relief
Valve
Outlet
Inlet
"Y" Strainer
To Drain
Optional
Fused
Disconnect
Optional
Fused
Disconnect
Maintain area
above Access
Panel for height
"C" to be clear of
obstructions
Rotate outlet 90˚
during installation
for adequate
clearance
Suggested Installation Configuration
Components provided by installer unless otherwise specified.
Reference the product options sections or contact your local Bradley
Representative for product options.
Access Panel
Dim. "A" Dim. "B" Dim. "C"
36kW 60"(1524) 48"(1219) 36"(914)
54kW 60"(1524) 48"(1219) 36"(914)
63kW 72"(1829) 60"(1524) 48"(1219)
72kW 60"(1524) 48"(1219) 36"(914)
108kW 60"(1524) 48"(1219) 36"(914)
126kW 72"(1829) 60"(1524) 48"(1219)
144kW 72"(1829) 60"(1524) 48"(1219)
Dimensions,
Plumbing
and Electrical
Configurations

7
Installation CNA-Series Tankless Heater
Keltech • 215-1814 Rev. C; ECN 150010 7/13/2015
Electric Installation
3
B
Using a hole punch, cut a hole the
proper size for conduit connection;
large enough for the wire size for each
heater. The connectors need to be rated
NEMA4/4X to ensure proper sealing of
the enclosure..
AOpen enclosure door.
CRun wires through the appropriate size
conduit.
DConnect wires to the system terminal
block or fused disconnect inside the
enclosure.
EConnect the ground wire to the stud
provided with the “Ground” label beneath it.
NOTICE! Any option that requires field wiring
must be done with 600V cable per
the schematic that was shipped with
the heater.
NOTICE! Use a 4-core cable or multi-stranded
machine tool wire from an approved
isolating 3-pole switch or circuit
breaker.
NOTICE! Make sure the electrical cable is the
correct size to carry 100% of the full
load current. See table for proper
wire sizes.
WARNING All Keltech heaters must be fused in accordance with National Electric Code (NEC) for the
full load amperage listed on the nameplate rating for each heater.
WARNING Failure to properly ground the unit(s) per the National Electric Code could result in injury or
death.
CNA & CNAR ELECTRICAL SPECIFICATIONS FOR HEATER**
Model Voltage Amps kWatts Min Wire
Size
CNA-363/600D 600 35 36 8 AWG*
CNA-543/600D 600 52 54 6 AWG*
CNA-633/600D 600 61 63 4 AWG*
CNA-723/600D 600 69 72 4 AWG*
CNA-1083/600D 600 104 108 2 AWG*
CNA-1263/600D 600 121 126 1 AWG*
CNA-1443/600D 600 139 144 1/0 AWG*
CNA-363/480D 480 43 36 6 AWG*
CNA-543/480D 480 65 54 4 AWG*
CNA-633/480D 480 76 63 4 AWG*
CNA-723/480D 480 87 72 3 AWG*
CNA-1083/480D 480 130 108 1 AWG*
CNA-1263/480D 480 152 126 1/0 AWG*
CNA-1443/480D 480 174 144 2/0 AWG*
CNA-363/415D 415 38 27 8 AWG*
CNA-543/415D 415 56 40 6 AWG*
CNA-633/415D 415 65 47 4 AWG*
CNA-723/415D 415 75 54 4 AWG*
CNA-1083/415D 415 113 81 2 AWG*
CNA-1263/415D 415 131 94 1 AWG*
CNA-1443/415D 415 150 108 1/0 AWG*
CNA-363/400D 400 36 25 8 AWG*
CNA-543/400D 400 53 37 6 AWG*
CNA-633/400D 400 64 44 4 AWG*
CNA-723/400D 400 72 50 4 AWG*
CNA-1083/400D 400 108 75 2 AWG*
CNA-1263/400D 400 126 87 1 AWG*
CNA-1443/400D 400 144 100 1/0 AWG*
CNA-363/380D 380 35 23 8 AWG*
CNA-543/380D 380 50 33 6 AWG*
CNA-633/380D 380 59 39 6 AWG*
CNA-723/380D 380 68 45 4 AWG*
CNA-1083/380D 380 103 68 2 AWG*
CNA-1263/380D 380 120 79 1 AWG*
CNA-1443/380D 380 137 90 1/0 AWG*
* Based on the NEC Table 310.15 for 75°C insulated wire @ 30°C Ambient
** CNAR (reverse models) electrical specifications are same as CNA heater
models.

8
CNA-Series Tankless Heater Installation
7/13/2015 Keltech • 215-1814 Rev. C; ECN 150010
Start Up Check List
4
Plumbing
System is set in a vertical, level, and upright position with the outlet located at the top. System is mounted by
legs (2) bolted to the floor (3/8" dia. minimum).
Confirm installation of shutoff valve above (upstream of) the union on the inlet connection. Confirm installation of
a Y-strainer (100 mesh screen) or inline filter (150 micron) between the inlet shutoff valve and the heater.
Pressure and temperature relief valve is installed on tepid water outlet immediately following the union. No valve
or restriction is between the relief valve and the system or the relief valve and drain. Shutoff valve is installed
after pressure and temperature relief valve on outlet if required by local or national plumbing codes.
If the hot water process is not at the highest point in the plumbing loop, then an automatic air vent valve must be
added at the highest point in the system plumbing loop to eliminate trapped air.
Electrical
Verify supply voltage matches the indicated voltage on the Serial Tag. Serial Tag is located within the heater
enclosure on the upper right corner of the back plate (mounting plate). Voltage can also be verified on the SCCR
Tag on the door of the heater.
Appropriate conduit is installed properly, secured and sealed to unit enclosure per NEC and hazard
location requirements.
Appropriate conductors for unit routed through conduit and secured to power block inside the enclosure. All
electrical is installed in accordance with national and local electrical codes, including fuse size and rating.
Appropriate earth ground is installed to the lug provided on enclosure backplate.

9
Installation CNA-Series Tankless Heater
Keltech • 215-1814 Rev. C; ECN 150010 7/13/2015
Start Up
5
ASlowly turn on water supply to the unit
with the enclosure door open and the
breaker in the off position.
CTurn off the connected process and
check the entire system to verify leak-free
installation.
DClose enclosure door and secure.
Depress the Emergency Stop Button.
FEnergize the electrical service to the unit
by switching on the breaker.
GPull out Emergency Stop Button. Unit is
now in the ready state.
B
Slowly turn on the water outlet valve,
activate the connected process requiring
heated water (faucet, shower, etc.), then
flush the system for 5 minutes to ensure all
air is purged from the system.
NOTICE! Failure to bleed air properly
will damage elements and
cause heater malfunction.
Be sure that plumbing and electrical are complete per Start Up Check List.
NOTICE! If your heater is mounted in an area
where freezing temperatures are possible,
an ENHT Freeze Protection Option is
strongly recommended and the heater
must be powered at all times to be
Freeze Protected. If continuous power is
not possible, do not allow the heater to
remain full of water. Freezing of the heater
can cause serious damage.
WARNING Make sure the breaker for the heater is OFF.
I
When startup is complete, leave circuit
breaker in the ON position and the
Emergency Stop Button on the door
pulled out. The Green power light should
be illuminated.
HTurn on the connected process; observe
output temperature rise to setpoint.
Top portion of temperature controller
displays output temperature, bottom
displays setpoint temperature.
EIf your heater has the EXP2CFPM
option and is located in a Class I
Division 2 area, please review Special
Installation & Operation Instructions
section for all proper electrical
connections and sealing to ensure
the installation will provide proper
protection. Proceed to Step F once you
have completed the steps in the Special
Installation & Operation Instructions or if
you do not have this option.

10
CNA-Series Tankless Heater Installation
7/13/2015 Keltech • 215-1814 Rev. C; ECN 150010
Digital Controller Operation
6
The preprogrammed digital controller is mounted through the bezel on the enclosure door. The digital
controller will be powered but the bottom display will read OFF until water is flowing through the heater.
The bottom display will then display the setpoint temperature (See Digital Controller Operation section for
more information).
Description Upper Display Lower Display Function
EZ Key Toggles output on/off
Setpoint Up Button Increases output temperature
Setpoint Down Button Decreases output temperature
Infinity Key Back to Home page
Advance Key Advances through parameter prompts
Auto, Man, Off C.r71 Turns Control Loop On/Manual/Off
XX.X% h.Pr1 Heater Power %
no AUt1 Autotune (Contact Factory)
C or F C_F1 Change Temperature Units from F to C
Output Indicators (1-5) Output 1,2,3,4 or 5 are active and operating if
these LEDs are illuminated.
Setpoint Temperature
(Lower Display)
Displays:
• Setpoint
• Percent Power
• Temperature units F or C
• Menu prompt name
• Alarm code
Output Temperature
(Upper Display)
Displays:
• Actual process temp. of outgoing water
• Prompt parameter value
• Error code (feature disabled)
Output Indicators
Output Temp.
Output
Temp. Output
Temp.
No Flow
Setpoint
Temp.
Setpoint Temp.
Setpoint Up
Setpoint Down
Advance KeyInfinity Key
EZ Key
Layout Diagram ON - Heating OFF - No Flow
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5

11
Installation CNA-Series Tankless Heater
Keltech • 215-1814 Rev. C; ECN 150010 7/13/2015
Perform Operational Test No. 1
Perform Operational Test No. 2
7
8
AStart the water flow through the heater by
starting the process or fixture this heater is
connected to in order to activate heater.
ATurn on hot water faucet/fixture/process
(min flow rate of 1.5gpm). The heater should
activate immediately.
C
Press the up or down arrow keys to
adjust the set temperature. The controller
displays the temperature of water
measured at the outlet.
BTurn off hot water faucet/fixture/process.
The flow sensor will deactivate and shut
off power to the heater.
D
Test water temperature and stability at
outlet by viewing the display. Controller
displays (in red) the temperature of water
exiting the heater.
B
When flow rate reaches approximately
1.5gpm, the flow sensor recognizes this
condition and begins the heating process.
When the flow sensor activates:
• Green bank energized lights illuminate on the
front bezel verifying power supply connection to
the heating elements via the solid-state relays.
• Element load lights may be solid or flash
in unison as heating elements modulate
depending on the hot water demand.
• Digital temperature controller shows water
temperature. Additional programming is
not necessary.
Located on the panel are one (36-63kW)
or two (72kW-144kW) green ready lights.
When illuminated, the safety circuit is
engaged and ready for use.
Heater will not energize heating elements if the
inlet water temperature is equal to or greater than
the temperature set on the digital controller .
If the water flow exceeds maximum heating capacity of the heater, the temperature of water at the outlet
may be lower than the temperature selected on the controller. See table below to determine maximum
temperature rise capabilities.
Each model has precise specifications for temperature rise capabilities.
Temperature Rise (GPM & F°)
Models 480/600V kW 2 gpm
ΔT °F
4 gpm
ΔT °F
6 gpm
ΔT °F
8 gpm
ΔT °F
10 gpm
ΔT °F
12 gpm
ΔT °F
15 gpm
ΔT °F
20 gpm
ΔT °F
25 gpm
ΔT °F
30 gpm
ΔT °F
35 gpm
ΔT °F
CNA-36 36 122 62 40 30 24 20 16 12
CNA-54 54 93 60 45 37 31 24 18 14
CNA-63 63 107 71 53 43 35 29 21 17 14
CNA-72 72 124 80 80 49 40 33 24 20 16 14
CNA-108 108 120 90 74 61 49 36 29 24 21
CNA-126 126 143 107 86 71 57 43 34 28 25
CNA-144 144 120 96 82 66 49 39 33 28
Temperature Rise (lpm & C°)
Models 480/600V kW 7.6 lpm
ΔT °C
15.1 lpm
ΔT °C
22.7 lpm
ΔT °C
30.2 lpm
ΔT °C
37.8 lpm
ΔT °C
45.4 lpm
ΔT °C
56.7 lpm
ΔT °C
75.6 lpm
ΔT °C
94.5 lpm
ΔT °C
113.4 lpm
ΔT °C
132.5 lpm
ΔT °C
CNA-36 36 68 34 22 17 13 11 9 7
CNA-54 54 52 33 25 21 17 13 10 8
CNA-63 63 59 39 29 24 19 16 12 9 8
CNA-72 72 69 44 44 27 22 18 13 11 9 8
CNA-108 108 67 50 41 34 27 20 16 13 12
CNA-126 126 79 59 48 39 32 24 19 16 14
CNA-144 144 67 53 46 37 27 22 18 16
CNA-Series

12
CNA-Series Tankless Heater Installation
7/13/2015 Keltech • 215-1814 Rev. C; ECN 150010
Output heating capacity is reduced if these heaters are installed on 415V, 400V or 380V 3-ph.
Contact the factory to supply this information.
Satisfactory performance of the heater is dependent upon a specific flow rate vs temperature rise capability. If the
desired temperature is not achieved, please verify the following:
1. Circuit breaker is on and rated for the maximum power draw.
2. Heater is drawing the proper current for the supply voltage on all 3 phases.
3. All 3 phase indicator lights are lit (not flashing) indicating maximum power draw and maximum
amperage is being drawn.
4. Flow rate and temperature rise in the water heating process are compatible with the heater specifications.
5. Verify there is no additional supply of cold water entering the line downstream of the heater.
Temperature Rise (GPM & °F)
Models 480/600V Total kW 4 gpm
ΔT °F
8 gpm
ΔT °F
12 gpm
ΔT °F
16 gpm
ΔT °F
20 gpm
ΔT °F
24 gpm
ΔT °F
30 gpm
ΔT °F
40 gpm
ΔT °F
50 gpm
ΔT °F
60 gpm
ΔT °F
70 gpm
ΔT °F
CNA & CNAR-108
(108 kW each) 216 120 90 74 61 49 36 29 24 21
CNA & CNAR-126
(126 kW each) 262 143 107 86 71 57 43 34 28 25
CNA & CNAR-144
(144 kW each) 288 120 96 82 66 49 39 33 28
Temperature Rise (lpm & °C)
Models 480/600V Total kW 15.1 lpm
ΔT °C
30.3 lpm
ΔT °C
45.4 lpm
ΔT °C
60.6 lpm
ΔT °C
75.7 lpm
ΔT °C
90.8 lpm
ΔT °C
113.6 lpm
ΔT °C
151.4 lpm
ΔT °C
189.3 lpm
ΔT °C
227.1 lpm
ΔT °C
265 lpm
ΔT °C
CNA & CNAR-108
(108 kW each) 216 67 50 41 34 27 20 16 13 12
CNA & CNAR-126
(126 kW each) 262 79 59 48 39 32 24 19 16 14
CNA & CNAR-144
(144 kW each) 288 67 53 46 37 27 22 18 16
CNA-SKID Series System (includes CNA and reverse configuration CNAR)

13
Installation CNA-Series Tankless Heater
Keltech • 215-1814 Rev. C; ECN 150010 7/13/2015
Product Options
GF (Ground Fault): Detects electrical leakage from external sources to protect equipment, electronics, and the heat
exchanger from being damaged in the event of a power fault. After turning on water, then power, test ground fault:
1. Press GF Test button.
2. Watch for ground fault light to illuminate and Bank Ready light(s) to shut off. The Ground Fault system is active
and in working order.
3. Press the GF Reset button, hold for 2 seconds and release to reset ground fault.
ENHT Freeze Protection (ENHT & ENHT30): ENHT offers protection to -20°F (-28°C). The ENHT30 offers protection to
-30°F (-34°C). Each level of protection utilizes the normal heater supply voltage. No additional dedicated circuit to the unit
is required during field installation. Freeze protection (ENHT option) includes an internally insulated NEMA 4/4X enclosure
and thermostatically controlled forced air heater to maintain internal temperatures above freezing. ENHT options also
include a connection point for DCS monitoring. In the event of a power interruption or ENHT system failure when internal
enclosure temperatures reach 40°F (4.4°C) or lower, the unit will notify a facilities control/monitoring system that the unit is
unable to maintain freeze protection. Regardless of state of power to the unit, this warning notifies maintenance personnel
and provides an opportunity to correct the condition before any damage occurs to the unit.
NOTICE! With this option, three phase power must be continuously applied to the heater for the internal
freeze protection heater to operate properly and provide protection. If three phase power cannot
be continuously applied, the heat exchanger must be completely drained of water and electrically
locked out or damage from freezing may occur. Use Start Up procedure to restart this equipment.
This option does not require a separate electrical circuit.
NOTICE! Failure to install these options properly, to maintain power at all times or to connect the contacts
provided on ENHT heaters correctly to the BMS may result in damage to the heater and void
the warranty. Please utilize the temperature sensor contacts (N.O.) that can provide a signal to
a remote device when temperature inside the cabinet drops below 40°F (4°C) and be aware of
freezing conditions in your area (Reference Schematic). The contacts will open and notify you that
the operations of the system should be verified.
FDS Fused Disconnect: Internal fused disconnect interlocks with enclosure door when energized, prohibiting access
to a live cabinet. Select the FDS option for an additional level of safety and convenience at the heater location.
T170, T180 & T190 High Temperature Options: Reach and maintain temperatures as high as 190°F.
D1 Control Interface: Provides 4–20ma communication interface with temperature controller.
TE & TE2 Corrosive Fluid Protection: The TE option is a PFA Teflon®coated heat exchanger with bright annealed
stainless steel elements,FDA Approved (Use for deionized water or mild corrosive fluid applications). Similar to TE,
the TE2 option is a single layer of Xylan Fluoropolymeric coated heat exchanger with bright annealed stainless steel
elements, FDA Approved for Food Contact (Use in deionized water applications).
EXP2CFPM (Continuous Flow Explosion Proof Purge System): Keltech's EXP2CFPM option makes heaters
compliant for classified areas: Class I Division 2, Groups A, B, C, D, Temp Code: T5. The Purge System requires a
supply of clean instrument air or inert gas (provided by installer). This supply maintains a positive internal pressure
and prevents the enclosure from filling with flammable gasses, dusts or vapors from the ambient environment.
Complete installation provided in this manual.
HLW (ASME Certified Heat Exchanger): Available on CNA-63 and larger. The heat exchanger is made of special
brass and certified by ASME inspector for quality of workmanship.
N4X (NEMA 4X Enclosure): Corrosion resistant enclosure made of stainless steel and ideal for harsh environments.
If a trip occurs under normal operation DO NOT RESET Ground Fault without evaluation and service.
Normal state is Ground Fault light OFF, Bank Ready lights ON.

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CNA-Series Tankless Heater Installation
7/13/2015 Keltech • 215-1814 Rev. C; ECN 150010
Maintenance
Preventative maintenance is important for optimal performance of the heater. To ensure the heater works properly,
always keep the inside of the enclosure dry. Moisture inside an enclosure increases the humidity, which condenses
on cooler surfaces. This can cause electrical problems and reduce the efficiency of enclosure insulation. To prevent
problems perform the following:
• Verify the interior of the enclosure is dry.
• Verify there are no leaks in seals of enclosure and that in high humidity environments all enclosure egresses are
properly sealed.
• Ensure plugs are in place on back side of enclosure.
• Check seals monthly during temperatures above 32°F (0°C) and weekly during temperatures below 32°F(0°C).
Check internal freeze protection system(ENHT, ENHT30) prior to first seasonal freeze for proper performance. The
external heater and internal thermostat are factory set at 55°F(13°C). Check weekly during temperatures below
32°F (0°C). See Information in Product Options section for additional information on freeze protection.
• Bimetal manual reset safeties mounted to the heat exchangers may trip at temperatures below 32°F on heaters
equipped with ENHT or ENHT30. The bimetal manual resets are set to trip at 175°F(79°C). Heat trace installed on
piping can heat water to temperatures above 100°F(38°C), causing the manual reset safeties to trip. Reset bimetal
manual safeties and lower heat trace temperature to below 175°F.
• All heaters require filtration of 150 microns or smaller to ensure proper operation. Y-strainers or additional filtration
should be verified and cleaned at least every 6 months or more often in areas where hard water sediment is
present in the water.
To clean the Y-Strainer:
1. Turn the power off at the circuit breaker panel.
2. Shut off the installer supplied cold water isolation valve to the heater.
3. Relieve pressure in the plumbing lines.
4. Position a bucket under the cold water inlet to catch any water that may still be in the pipe.
5. Loosen the plumbing connection on the Y-strainer to get to the screen.
6. Remove screen and clean out debris. Use a wire brush to clean smaller particles from the screen.
7. Once the screen is clean, put it back into the Y-strainer housing and secure the plumbing connection.
8. Before switching the power back on, bleed the air out of the lines by turning heater water supply back on and
the plumbing fixture or process farthest from the heater.
9. With the air purged, turn on all circuit breakers supplying the water heater.
• At the same time the Y-strainer or additional filtration is cleaned, it is a good practice to also check all valves
connected to the system. With no water flow through the heater, work both the inlet ball valves and the outlet gate
valves open and shut to break up any calcium deposits that may have formed from the valve being open for an
extended period of time. Power to the heater does not need to be turned off to do this.

15
Installation CNA-Series Tankless Heater
Keltech • 215-1814 Rev. C; ECN 150010 7/13/2015
Troubleshooting for Controller
Problem Solution
No Power Verify power is on.
Check continuity of all internal fuses in control
transformer, heating elements or optional Fused
Disconnect circuits.
Check all field service circuit breakers or fuses.
Check the safety interlock door switch to make sure
that lack of power is not due to misadjustment or open
enclosure door.
Check system temperature limit control to make sure
it has not activated due to excessive heat exchanger
temperature or faulty sensor.
Check for loose or disconnected wires.
Check the incoming service connection. Voltage must
match name plate rated voltage. Labels are located on
the cabinet door (SCCR) and on upper left of back plate
(Serial Number Label).

16
CNA-Series Tankless Heater Installation
7/13/2015 Keltech • 215-1814 Rev. C; ECN 150010
Troubleshooting using the Flow Limit Control Board (FLCB)
Problem Solution
The heater does not work or works intermittently. Check that the flow sensor located at the inlet is spinning
with water running. Check if in Low flow (> 1.5 gpm) that
the FLCB light is on. If in High flow (> 15gpm) both the low
flow light and high flow lights will be illuminated.
Check that water flow through the heater is adequate to
activate the flow sensor at 1.5gpm.
Check that the heater is wired with the proper breaker and
wire size. Refer to Electrical Specifications table for proper
requirements.
Check that the unit is receiving voltage from all 3 phases
of the power source. A load voltage reading is also helpful.
Element Load Bank 1–2 or 3–4 is not energized. Check FLCB with corresponding light indicated:
Bank 1–2 on the front bezel = Bank 1 on the FLCB
Bank 3–4 on the front bezel = Bank 2 on the FLCB.
If the light is off and there is power on. Check if water
temperature is greater than 175˚F. Decrease water
temperatures and restart.
If the above steps do not solve the problem, some additional checks may be performed. Follow the
schematic to perform the following continuity checks:
Emergency stop switch.
Door guard.
High temperature bimetals (Manual Reset Safeties).
Optional ground fault breaker must be in the closed position for the unit to work.
All internal breakers must be in the ON position for the unit to work.
For additional information on Troubleshooting or other information, please call Keltech Inc. technical support at
1-800-999-4320. Please have Model No. and Serial No. available when seeking technical assistance. Serial No.
tag is located in the enclosure on the upper left hand corner of the back plate. Please record and maintain this
information at all times:
CNA- Model No.
Serial No.
High Temp.
Limit Senser
Input
Bank 2 Over
Temp. (OT)
Bank 1 Over
Temp. (OT)
High Flow
Status
Low Flow
Status
Purge/Dump
(SNA Models
Only)

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.

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CNA-Series Tankless Heater Installation
7/13/2015 Keltech • 215-1814 Rev. C; ECN 150010
Purge Gas Supply Notes
An alarm shall be provided to indicate failure of the protective gas supply to maintain the required pressure. Piping for
the protective gas shall be protected against mechanical damage.
Where the compressor intake line passes through a classified location, it shall be constructed of noncombustible
material, designed to prevent leakage of flammable gases, vapors, or dusts into the protective gas, and protected
against mechanical damage and corrosion.
The electrical power for the protective gas supply (blower, compressor, etc.) shall be supplied either from a separate
power source or from the protected enclosure power supply prior to any service disconnects of the protected
enclosure. Any protected enclosure that can be isolated from the protective gas supply shall be equipped with an
alarm. Where an alarm is used to indicate the loss of pressure in the cabinet:
• The alarm shall be located at a constantly attended location.
• The alarm actuator shall take its signal from the protected enclosure and shall not be installed between the
enclosure and the protective gas supply.
• The alarm actuator shall be mechanical, pneumatic, or electrical.
• Electrical alarms and electrical alarm actuators shall be approved for the location in which they are installed.
• No valves shall be permitted between the alarm actuator and the enclosure.
Intrinsically Safe (IS) Installation
1. Electrical equipment connected to associated apparatus should not use or generate more than 250 volts.
2. Installation shall be in accordance with the manufacturer's instructions and the National Electrical Code (NFPA 70).
3. For guidance on Installation see ANSI/ISA RP12.6 (Installation of IS Instrument System in Class I
Hazardous Locations).
4. Voc or Vt of associated apparatus is less than Vmax
Isc or IT of associated apparatus is less than Imax
Ci plus capacitance of interconnecting cabling is less than Ca of the associated apparatus
Li plus inductance of interconnecting cabling is less than La fo the associated apparatus
5. "Simple Apparatus" is a device that will not generate or store more than 1.2V, 0,1A, 25mW or 20uJ
Hazardous Location
Class I , Division 2
Groups A, B, C, D
T5 Hazardous (classified) Areas
MiniPurge: Option Code /IS
Vmax = 30v
Imax = 350mA
Ci = 0 Li = 0
Non- Hazardous Location
(or suitably protected enclosure)
Power Supply
Outputs to relays or
power contactors
Intrinsically Safe
Interface Unit
Simple apparatus
device

19
Installation CNA-Series Tankless Heater
Keltech • 215-1814 Rev. C; ECN 150010 7/13/2015
IS Installation continued…
All quarter turn latches in the door of the PE must be fully latched for proper operation. Power to the PE must be
turned off before opening the enclosure.
WARNING This Pressurized Enclosure shall not be opened unless the area is known to be free of
flammable materials or unless all devices within have been de-energized.
Power shall not be restored after the enclosure has been opened until the enclosure has been purged for allotted
time (See table below). Time begins when pressure indicator turns green after the door of the enclosure has been
closed and fully latched.
WARNING Ignition of potentially explosive gas/air mixtures may result if power is turned on before the
allotted purge time!
Expo Technologies CF systems have a Minimum Pressure Sensor set to a pressure of at lease 0.1" WC (0.25bars). When
the PE pressure is above this set point the sensor produces a positive Pressurized signal. This is displayed on the Red/
Green indicator located on the Purge System. This signal can be used to operate an electrical contact for a remote Alarm.
This signal may be supplied to the pressure operated switch suitable for Intrinsically Safe circuit in accordance. When the
enclosure pressure falls below the set point of the sensor, the Pressurized signal is removed, and the Alarm conditions
occurs. This Alarm must be located where it can be readily observed according to NFPA496 requirements. No valves may
be fitted between the Expo Technologies system and the alarm switch.
WARNING Never turn on the power without purging first, unless you have proved the interior of the PE is gas
free and checked that the “Pressurized” indicator is green!
Commissioning Test
Commissioning Continuous Flow Keltech Option EXP2CFPM System:
1. Open the air or gas supply shutoff valve.
2. Adjust the Flow Control Valve (FCV) so that the enclosure pressure rises to the point where the "Pressurized"
indicator turns green.
3. Lower the PE pressure until the Pressurized indicator turns Red.
4. Open the FCV again and set the PE pressure to a level somewhere between the Minimum Pressure
Sensorset point and the RLV opening pressures. This working pressure is not critical. Enough pressure to keep
the“Pressurized” indicator Green is sufficient.
5. On EXP2CFPM Purge System the timing function if performed by the user. The user must ensure that the time
delay between the indicator turning Yellow and the application of power to the PE is not less than the minimum
time required to purge the PE as shown in the table below.
Normal Operation: Turn the air supply valve ON to start or OFF to stop the system. The user must close the Power
Switch only after the enclosure has been pressurized and purged sufficiently to ensure that the interior of the enclosure
is gas free. It is the operator’s responsibility to shut off the power as soon as possible after a pressure failure.
PURGE TIME CHART - EXP2CFPM Option
for use with EXPO Mini Z Purge 1ZCF/pm/IS
Model/Enclosure
Group Size
Cubic
Feet
Volume
Exchanges
X 4
Orifice
Size
Orifice
No.
Purge
Time
(Minutes)
CNA-36-54 10 40 0.9 #2 44
CNA-63 12.5 50 0.9 #2 55
CNA-72-108 10 40 0.9 #2 44
CNA-126-144 12.5 50 0.9 #2 55

20
CNA-Series Tankless Heater Installation
7/13/2015 Keltech • 215-1814 Rev. C; ECN 150010
Special Installation Maintenance
Routine Maintenance of the System (Every 6 months)
Recommended maintenance of the systems is as follows:
Repeat Commissioning test at least every six months. The test includes checking the opening pressure of the Relief
Valve, setting of the Minimum Pressure Sensor, the “Normal Working Pressure” of the enclosure. Test that the interlock
and alarms function correctly.
Check the Relief Valve and any other Spark Arrestors. Remove any debris or corrosion, or replace the Spark Arrestor.
Check the condition of the air supply filter element. Clean or replace it as necessary.
Periodic Maintenance (Every 18-24 months)
At least every two years, the following additional checks are recommended:
Apparatus (Heater, Purge Systems, Alarms etc.) is suitable for the Hazardous Location.
There are not unauthorized modifications.
The source of air is uncontaminated.
The interlock and alarms function correctly.
Approval labels are legible and undamaged.
Adequate spare parts are carried.
The action of pressure failure is correct.