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16

SNA-Series Tankless Heater

 Installation

10/17/2014 

Keltech • 

215-1815 Rev. B; ECN 130011

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 Tables 5 & 6) . 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 ( .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 (See Figure 
6) . 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 Leakage Compensation (LC) and Continuous Flow/High Purge Keltech Options EXP2LC 
and EXP2 Systems:

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 EXP2 and EXP2LC Purge Systems 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 Tables 5 & 6 . 

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 - EXP2 Option 

for use with EXPO Mini Z Purge 1ZCF/bp/IS

Model/Enclosure 

Group Size

Cubic 

Feet

Volume 

Exchanges 

X 4

Orifice 

Size

Orifice 

No .

Purge 

Time 

(Minutes)

SNA-36-54

10

40

0 .9

#2

44

SNA-63

12 .5

50

0 .9

#2

55

SNA-72-108

10

40

0 .9

#2

44

SNA-126-144

12 .5

50

0 .9

#2

55

PURGE TIME CHART - EXP2LC Option 

for use with EXPO Mini Z Purge 1ZLC/bp/IS

Model/Enclosure 

Group Size

Cubic 

Feet

Volume 

Exchanges 

X 4

Purge 

Time 

Minutes

SNA-36-54

10

40

6

SNA-63

12 .5

50

6

SNA-72-108

10

40

6

SNA-126-144

12 .5

50

6

TABLE 5

TABLE 6

Summary of Contents for SNA-108

Page 1: ...Options 11 12 Maintenance 12 Troubleshooting 12 13 Special Installation Operating Instructions 14 17 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 Separate parts from packaging and...

Page 2: ...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 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 follo...

Page 3: ... 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 NOTE 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 ensure internal freeze protection components are ac...

Page 4: ...emperature relief valve on hot water outlet immediately following the union NOTE Valve must empty into a drain See Figure 2 B Remove air by re installing drain plugs and open inlet supply valve to apply line pressure to heater Open fixture connected to the heater outlet for 5 minutes or until all air has been removed from the heater Fixture can be closed and power restored to the heater For best r...

Page 5: ...ystem or at any drop to eliminate trapped air Components Needed 5 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 Elbows nipples and fittings as needed 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 ...

Page 6: ...e rating for each heater CAUTION To avoid damage to the electronics or internal wiring do not perform any brazing or sweat soldering inside the enclosure ELECTRICAL SPECIFICATIONS FOR HEATER PHASE 3 Model Voltage Amps kWatts Min Wire Size SNA 363 600D 600 35 36 8 AWG SNA 543 600D 600 52 54 6 AWG SNA 633 600D 600 61 63 4 AWG SNA 723 600D 600 69 72 4 AWG SNA 1083 600D 600 104 108 2 AWG SNA 1263 600D...

Page 7: ...lief 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 th...

Page 8: ...cet shower etc then flush the system for 5 minutes to ensure all air is purged from the system CAUTION 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 IMPORTANT If your heater is mounted in an area where freezing temperatures are possible an ENHT Freeze Protection Option should be specified He...

Page 9: ...ome page Advance Key Advances through parameter prompts Auto Man Off C r71 Turns Control Loop On Manual Off Disabled on SNA Models XX X h Pr1 Heater Power Disabled on SNA Models no AUt1 Autotune Contact Factory Disabled on SNA Models 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...

Page 10: ...imately 10 psi For example if the high limit pressure is 40 psi adjust the low limit pressure to 30 psi with the pressure switch located on the supply pump 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 ...

Page 11: ...r 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 NOTE If a trip occurs under normal operation DO NOT RESET Ground Fault without evaluation and service...

Page 12: ...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 Ve...

Page 13: ...ndicated 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 Follow the schematic to perform the following continuity checks Emergency stop switch Door guard High temperature bimetals Manual Reset Safeties Optional ground fault...

Page 14: ...inlet fitting here FIGURE 6 EXP2 EXP2LC 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 See Figure 6 3 There are two ...

Page 15: ...sure 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 FIGURE 7 1 Electrical equipment connected to associated apparatus should not use ...

Page 16: ...proved the interior of the PE is gas free and checked that the Pressurized indicator is green Commissioning Test Commissioning Leakage Compensation LC and Continuous Flow High Purge Keltech Options EXP2LC and EXP2 Systems 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 Low...

Page 17: ...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...

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