12
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 .
