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 18 • Commercial Electric Water Heater Use and Care Guide

INSTALLATION

Step 9:

Make electrical

 

connections

WARNING! Working on an 

energized circuit can result in severe 

injury or death from electrical shock.

NOTICE: 

Do not turn electrical power 

on unless you are sure all of the air 

is out of the tank and the tank is 
completely full of water. If power is 
applied before the tank is completely 
full of water, the upper element will 

burn out (Dry Fire).

1

Be sure the electrical power 
to the water heater is turned 
OFF at the circuit breaker 

panel (or remove the circuit’s fuses).

2

Using a non-contact circuit 
tester, check the wiring to 
make certain the power is OFF.

3

Check the water heater’s 
data plate and ensure that 
the voltage, wiring size 

(ampacity) and circuit breaker rating 
and type are correct for this water 
heater. Refer to the wiring diagram 
located on the water heater for the 
correct electrical connections. Ensure 
that wire sizes, type, and connections 
comply with all applicable local codes. 

In the absence of local/provincial 

codes, follow the “Canadian Electrical 
Codes” CSA C22.1 current. 

4

Open the upper access panel 
and fold away the insulation 

to access the electrical 

junction box.

Figure 18 - 

The water heater’s electrical 

requirements can be determined from the  data 

plate.

5

Install wiring in an approved 
conduit (if required by local 
codes). Use a UL listed or CSA 

approved strain relief to secure the 
electrical wiring to the water heater.

6

Connect the ground wire to 
the green ground screw. 
Connect the power wires to 

the terminal block for single-phase or 
3-phase operation as desired (see 
page 10).

Figure 19 - 

Connecting the electrical wires.

Fold the insulation back in 
place, close the upper access 
panel and secure with the 

screw provided. 

WARNING! Be sure cover is secured 

to reduce the risk of fire and electric 

shock.

NOTICE: The tank must be 

completely empty of air and 

full of water before connecting 

electrical power to avoid “Dry 

Firing.” Dry Firing may result in 

the upper element burning out.  

This is a common installation 

mistake. After you make the 

water connections, but before 

you connect the electrical power, 

open a hot water faucet and let 

the water run full until all the 

air is removed. Let the “hot” 

water run full for three minutes 

or longer before connecting any 

electrical wires. A Dry Fired upper 

heating element is an installation 

error and is not covered under 

warranty.

If Dry Firing occurs, replace the 

upper heating element according 

to the instructions on page 25.

INS

TALLA

TION

7

Summary of Contents for DEJC-50

Page 1: ...T Read this manual and the labels on the water heater before you install operate or service it If you have difficulty following the directions or aren t sure you can safely and properly do any of this...

Page 2: ...ermostat access Lower Element and Thermostat access T P relief valve Water shut off Electrical junction box Expansion tank Drain pan discharge pipe Drain pan Drain valve T P discharge pipe Cold water...

Page 3: ...ANGER indicates hazardous situation that if not avoided will result in death or serious injury WARNING WARNING indicates a hazardous situation that if not avoided could result in death or serious inju...

Page 4: ...lly mix hot and cold water to limit the temperature at the tap Mixing valves are available from your local plumbing supplier Follow manufacturer s instructions for installation and adjustment of the v...

Page 5: ...s from plumbing or leaks from the water heater itself can damage property and could cause a fire risk If the water heater is subjected to flood conditions or the thermostat s have been submerged in wa...

Page 6: ...1 46 41 36 34 30 29 9 LPH 384 345 256 230 192 173 153 138 128 115 110 5000 5000 GPH 113 101 75 68 56 51 45 41 38 34 32 10 LPH 426 384 284 256 213 192 170 153 142 128 122 5500 5500 GPH 126 113 84 75 63...

Page 7: ...3 Before you start be sure you have and know how to use the following tools and supplies Plumbing tools and supplies appropriate for the type of water pipes in the plumbing system Threaded connectors...

Page 8: ...ALCULATING AMPERAGE OVERCURRENT PROTECTION The dual element heater is factory wired for connection to a three wire three phase delta branch circuit non simultaneous operation In addition a ground cond...

Page 9: ...Commercial Electric Water Heater Use and Care Guide 9 Approvals All models are listed by Underwriters Laboratories Inc Model and Rating DELC 30 40 50 DENC 30 40 DEJC 50 66 GETTING STARTED...

Page 10: ...10 Commercial Electric Water Heater Use and Care Guide Thermostat Wiring Diagram A 8 CIRCUIT FOR DUAL ELEMENT HEATER GETTING STARTED GETTING STARTED...

Page 11: ...ater supply line and adjust the water pressure control to between 50 60 psi 345 414 kPa If the property does not have a Pressure Reducing Valve install a PRV on the main water supply line and set it t...

Page 12: ...d can shut off the water heater s water supply if a leak occurs Figure 6 A suitable drain pan piped to an adequate drain can help protect flooring from leaks and drips Install a suitable drain pan ava...

Page 13: ...spect the drain pan pipes and surrounding area regularly and fix any leaks found Drain pans are available at local plumbing supplier Leaks are frequently in the plumbing system itself and not the wate...

Page 14: ...heater 1 Completely read all instructions before beginning If you are not sure if you can complete the installation seek assistance from any of the following sources Schedule an appointment with a qua...

Page 15: ...stall it to allow complete drainage of both the T P Relief Valve and the discharge pipe The discharge pipe must withstand 250 F 121 C without distortion Use only PEX copper or CPVC pipe Do not use any...

Page 16: ...ed polyethylene PEX Use fittings appropriate for the type of pipe in the plumbing system Do not use iron or PVC pipe they are not suitable for potable water 2 Connect the cold water supply using 3 4 i...

Page 17: ...Expansion Tank Figure 15 A Pressure Reducing Valve is required if the plumbing system s water pressure is above 80 psi 552 kPa Figure 16 The Thermal Expansion Tank should be pressurized with air to ma...

Page 18: ...o access the electrical junction box Figure 18 The water heater s electrical requirements can be determined from the data plate 5 Install wiring in an approved conduit if required by local codes Use a...

Page 19: ...h from electrical shock Check wires with a circuit tester to make sure power is off Open the electrical junction box and remove the lower thermostat access panel Do not remove the plastic personnel pr...

Page 20: ...temperature setting when you return CAUTION Hydrogen gas builds up in a hot water system when it is not used for a long period two weeks or more Hydrogen gas is extremely flammable If the hot water s...

Page 21: ...uit tester Turn the power off and close the electrical junction box If the water heater is not getting power contact a qualified person to have the wiring or circuit breakers checked 2 Check the upper...

Page 22: ...nections or melted dip tube usually found soon after new installation Plumbing leak Bad lower heating element or lower thermostat Low supply voltage Thermostatic Mixing Valves If the hot water is simp...

Page 23: ...be due to the tank overheating WARNING Do not cap or plug the T P relief valve or discharge pipe and do not operate the water heater without a functioning T P Relief Valve this could cause an explosi...

Page 24: ...cool Figure 25 Water Faucet WARNING Be sure the water runs cool before draining the tank to reduce the risk of scalding 3 Connect a garden hose to the drain valve and place the other end of the hose...

Page 25: ...or thermostat yourself have this work done by a qualified person To replace the heating element you ll need the following tools and supplies Figure 28 Non Contact Circuit Tester Always turn power OFF...

Page 26: ...remove the element Inspect the gasket for damage If the gasket is damaged replace the gasket and re install the element 12 Once the element is successfully installed and there are no leaks replace the...

Page 27: ...f Valve yellow label attached to T P Relief Valve Minerals in the water can form deposits that cause the valve to stick or create blocked passages making the T P Relief Valve inoperative Follow these...

Page 28: ...odel and serial number 2 Item number and part description Key No Part Description 1A ANODE ALUMINUM 1B ANODE MAGNESIUM SMR P72 AND S19 2 T P RELIEF VALVE 3 ELEMENT GASKET 4 ELEMENT 5 UPPER THERMOSTAT...

Page 29: ...expired portion of the warranty WHAT S NOT COVERED Problems caused by improper gas supply line sizing gas type venting connections combustion air voltage wiring or fusing Failure to follow applicable...

Page 30: ...30 Commercial Electric Water Heater Use and Care Guide NOTES NOTES...

Page 31: ...Commercial Electric Water Heater Use and Care Guide 31 NOTES NOTES...

Page 32: ...Copyright 2021 A O Smith All Rights Reserved...

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