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SNA-Series Tankless Heater Installation
10/17/2014 Keltech • 215-1815 Rev. B; ECN 130011
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:
• Keep interior of enclosure dry.
• Seal any weeping leaks in seals or walls. 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.
• Monitor Shower heater performance at each routine safety shower inspection.
• Verify the following lights illuminate with activation of the Shower or Eye/FaceWash:
• Green bank energized lights
• Digital display controller
• Red element load lights 1-4
• Green power light illuminated
• Verify that the heater activates the "TepidGuard" discharge port by purging water whenever the shower is deactivated. If
heater does not perform as expected, take appropriate corrective action by evaluating the cause and repair as necessary.
• 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 operation weekly during temperatures below
32°F (0°C). See Information in Product Options section for additional information on freeze protection.
• Manual Reset Safeties mounted to the heat exchangers may trip at temperatures below 32°F on heaters equipped
with ENHT or ENHT30. Manual resets are set to trip at 100°F(38°C). Heat trace installed on connected piping can
heat water to temperatures above 100°F(38°C), causing the manual reset safeties to trip. Reset Manual Safeties
and lower heat trace temperature to below 100°F.
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 it 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).
…continued from previous page
EXP2 (Explosion Proof Purge System): Keltech's EXP2 option makes heaters compliant for classified areas;
Class I Division 2, Groups A–D, 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.
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.
HLW (ASME Certified Heat Exchanger): Available on SNA-63 and larger. The heat Exchanger is made of special
brass and certified by ASME inspector for quality of workmanship.
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