OPERATING AND MAINTENANCE MANUAL FOR
INSTANTANEOUS ELECTRIC
CIRCULATION HEATER
ELECTRIC HEATER COMPANY
BASE MODEL “ CR ”
HUBBELL
ELECTRIC HEATER COMPANY
P.O. BOX 288
STRATFORD, CT 06615
PHONE: (203) 378-2659
FAX: (203) 378-3593
INTERNET: http://www.hubbellheaters.com/
-- IMPORTANT --
Always reference the full model number and serial number when calling the factory.
WARNING / CAUTION
1. Tank is to be completely filled with water and all air is to be vented before energizing.
2. Due to the rigors of transportation, all connections should be checked for tightness before heater
is placed in operation.
3. Safety relief valve must be installed in tapping provided.
4. The refractory material used in heating elements may absorb some moisture during transit,
periods of storage, or when subjected to a humid environment. This moisture absorption results
in a cold insulation resistance of less than twenty (20) megohms. If this heater has been
subjected to the above condition, each heating element must be checked for insulation
resistance before energizing. A low megohm condition can be corrected by removing the
terminal hardware and baking the element in an oven at 350°F -700°F for several hours or until
the proper megohm reading is obtained.
5. KEEP AWAY FROM LIVE ELECTRICAL CIRCUITS.
Do not perform any maintenance, make any adjustments, or replace any components inside the
control panel with the high voltage power supply turned on. Under certain circumstances,
dangerous potentials may exist even when the power supply is off. To avoid casualties, always
turn the power supply safety switch to off, turn the charge or ground the circuit before
performing any maintenance or adjustment procedure.
6. The unit is designed to operate at pressure not more than 150 psi.
7. Generalized instructions and procedures cannot anticipate all situations. For this reason, only
qualified installers should perform the installations. A qualified installer is a person who has
licensed training and a working knowledge of the applicable codes regulation, tools, equipment,
and methods necessary for safe installation of an electric resistance water heater. If questions
regarding installation arise, check your local plumbing and electrical inspectors for proper
procedures and codes. If you cannot obtain the required information, contact the company.
2
TABLE OF CONTENTS
SECTION TITLE PAGE #
I GENERAL DESCRIPTION AND CONSTRUCTION 5
II INSTALLATION 12
III SCHEDULED MAINTENANCE AND OPERATION 14
IV TROUBLESHOOTING 15
V SERVICING & REPLACEMENT OF PARTS 17
VI MISCELLANEOUS CHARTS AND FORMULAS 22
3
4 5
SECTION I - GENERAL DESCRIPTION AND CONSTRUCTION
GENERAL DESCRIPTION
This book describes a packaged electric heater that is a stationary, self-contained unit. The complete
assembly consists of the pressure vessel, immersion electric heating element, thermostat, safety relief
valve, safety high temperature cut out, magnetic contactor(s), power circuit fusing, fused low voltage
control circuit transformer, and any other required electrical operating control. Optional equipment may
be supplied with your unit. Please consult the product drawing for details specific to your assembly.
The unit is factory assembled, insulated, jacketed, wired, tested, and ready for electrical and plumbing
service connections.
CONSTRUCTION
PRESSURE VESSEL
Standard Vessel Construction:
The standard pressure vessel is constructed of all welded carbon steel, then hot dip galvanized for
added corrosion resistance. Units over 58 kW are designed and built in accordance with ASME Section
IV and stamped, certified, and registered with the National Board of Boiler and Pressure Vessel
Inspectors. The maximum allowable working pressure is stamped on the nameplate. The standard
working pressure is 150 psi (225 psi TP).
Optional Non-Ferrous Vessel Materials:
1. Copper-Silicon – A copper-silicon alloy offers tremendous longevity due to its ability to
withstand the cycling effects induced from changes in water temperature and pressure. This
material is suitable for storage of hot potable water in a variety of commercial and industrial
applications.
2. 90/10 Copper-Nickel – A 90% copper and 10% nickel alloy similar to copper-silicon, but with
added strength and corrosion resistance. Typically used in applications with corrosive
environments (salt water) or critical applications.
3. Stainless Steel – Stainless steel (type 304, 316, or 316L) is well suited for high purity
applications requiring a corrosion resistant tank with minimal leaching of impurities into the
water. Well suited for process, RO, and DI water systems in the pharmaceutical, food, and
electronic industries.
4. Other materials are available upon request.
Optional Working Pressures:
The pressure vessel may be supplied with optional working pressures (standard working pressure is 150
psi). See drawing for details.
VESSEL CONNECTIONS
The heater is supplied with separate cold water and hot water connections. A connection is provided for
mounting a combination safety temperature and pressure relief valve. An overflow line should be
utilized from the relief valve outlet to a floor drain. See drawing for locations and sizes.
OUTER SHELL, INSULATION, AND SUPPORTS
The pressure vessel is encapsulated in 2-inches of high-density fiberglass insulation. The protective
shell is constructed of galvaneel and is coated with a durable silver hammertone finish. The horizontal
configuration is supported on heavy-duty steel I-beam supports. Also available in a vertical
configuration or wall hung for off the floor installation.
HEATING ELEMENT
The heater is supplied with a flanged electric immersion heating element assembly, composed of
copper, incoloy, or stainless steel sheathed elements that are brazed or welded into a ANSI steel flange.
The heating element is fastened to a corresponding tank flange using a gasket and hex head steel bolts
and nuts. Specialized heating element construction may be included. These options include: special
watt density ratings, passivation, electropolishing, or special materials. See drawing for voltage, power
ratings, and special options.
ELECTRICAL ENCLOSURE A louvered control panel available in various sizes and with assorted types of handles is supplied. The standard cabinet is rated NEMA 1, but other NEMA rated enclosures are available, consult drawing for further information. A list of NEMA ratings are available in Section VI. An optional explosion-proof enclosure is available for hazardous locations.
FLOW SWITCH
The heater is supplied with a factory installed and wired
safety flow switch. This device will allow the immersion
heating element to energize only when there is sufficient flow
through the unit.
6
CONTROL THERMOSTAT
The control panel is supplied standard with a single-stage immersion thermostatic switch. As an
optional any of the following may be supplied; a four-stage immersion thermostatic switch, a solid-state
staging controller with thermistor, or a digital 1/16 DIN temperature controller with thermocouple. See
drawing for specific details. The single-stage immersion thermostat can be adjusted through a range of
100° - 190° F. A low range, (30° - 110° F), operating thermostat is also available in the single-stage
version. The four-stage immersion thermostat can be adjusted through a range of 100° - 250° F and is
capable of switching four circuits. The solid-state staging controller automatically brings on-line the
required number of heating steps in order to meet the hot water demand and will also operate each
circuit in a circular mode to allow for equal usage of all heating circuits. The thermostat is adjustable to
the desired temperature by turning the dial on the pot switch. A 1/16 DIN electronic temperature
control package may be installed. A separate manufacturer’s operating manual will be supplied with all
units except the single-stage immersion thermostat.
Single-Stage Immersion Thermostat Four-Stage Immersion Thermostat
1/16 DIN Digital Display
Solid State Staging Controller
7
TEMPERATURE HIGH LIMIT SWITCH
As a safety device, an immersion high temperature cut-off switch with manual reset, adjustable through
a range of 100° - 240° F, is provided. The high limit must be manually reset thereafter to restart the
heater. Optionally a 1/16 DIN digital controller may be used as a high-limit.
Manual Reset
MAGNETIC CONTACTOR
The magnetic contactor(s) is a heavy-duty resistive load type rated for
100,000 cycles. The contactor supplies power to the heating
element(s) based on the resistive load (non-inductive) of the heater
only when the thermostatic switch is engaged, thereby pulling in the
contacts until the desired temperature is reached. At this point, the
contacts will drop out, which in turn disconnects power from the
elements.
FUSED LOW VOLTAGE TRANSFORMER
A fused low voltage transformer may be supplied. This option
is used to step down higher voltages to 120-volt for safety
when working with control circuits.
8
INDIVIDUALLY FUSED ELEMENTS
To prevent the possibility of damage to control circuits and other elements in case of electrical
overloads, fuses may be supplied for each element. Two types of fuses may be used; a type NON for
voltages less than 250-volt or type JJS for voltage less than 600-volt.
Type JJS Type NON
LOW WATER CUT-OFF
Used as a safety device, the electronic low water cut-off is used to detect a low water situation and
disengage the operating coils in the magnetic contactor(s). Once the condition is remedied, the low
water cut-off switch is automatically reset.
Conductive Type Low Water Cut-Off Relay
OPTIONS
The following optional features may be included in your water heater. Reference included drawing
specific to your heater for further details.
Stainless Steel Jacket
An optional stainless steel outer jacket may replace the standard galvaneel covering. This optional
jacket may be painted.
9
On / Off Control Switch
A built-in non-fused On/Off disconnect switch may be supplied with the control panel to decrease the risk of injury when working with the control panel.
Built-In Circuit Breaker
A built-in circuit breaker may be provided with or without shunt
trip protection for protection from circuit overload.
Audible Alarm
An audible alarm may be installed on the outside of the control panel to give warning of an overtemperature condition.
Building Management System (BMS)
A Building Management System control package may be supplied for remote operation and alarm
capabilities.
Status Indicating Lamp(s) Optional status indicating lamps may be installed to show when the unit is on, when the heating element is energized, or if there is an alarm condition.
10
Silicon Control Rectifier
An SCR “zero fired” power controller for 0-100% proportional control of heaters may be supplied.
Dial Temperature and Pressure Gauge
A combination temperature (70° - 250° F) and pressure (0 – 200 psi) gauge with 2½-inch dial may be
supplied for in-line installation (shipped loose) or factory installed in the tank.
Special Customized Features
Please reference drawing for details.
11
SECTION II – INSTALLATION
WARNING / CAUTION
DO NOT TURN ON THE ELECTRIC POWER SUPPLY to this equipment until heater is
completely filled with water and all air has been released. If the heater is NOT filled with water when
the power is turned on, the heating elements will burn out.
For protection against excessive pressures and temperatures, local codes require the installation of a
temperature-and-pressure (T&P) relief valve certified by a nationally recognized laboratory that
maintains periodic inspection of production of listed equipment of materials, as meeting the
requirements for Relief Valves and Automatic Gas Shutoff for Hot Water Supply Systems. ANSI
Z21.22-1971. THE CUSTOMER IS RESPONSIBLE TO PROTECT PROPERTY AND
PERSONNEL FROM HARM WHEN THE VALVE FUNCTIONS.
All water heaters have a risk of leakage at some unpredictable time. IT IS THE CUSTOMER'S
RESPONSIBILITY TO PROVIDE A CATCH PAN OR OTHER ADEQUATE MEANS, SO THAT
THE RESULTANT FLOW OF WATER WILL NOT DAMAGE FURNISHINGS OR PROPERTY.
HEATER PLACEMENT
1. Place the heater on a solid foundation in a clean, dry location nearest to the point of most
frequent hot water use.
2. The heater should be protected from freezing and waterlines insulated to reduce energy and
water waste.
3. Leave sufficient clearance for element withdrawal, if necessary.
4. Do not install in an area where flammable liquids or combustible vapors are present.
PIPING INSTALLATION
NOTE: The most effective means for preventing deterioration from accelerated corrosion due to
galvanic and stray current is the installation of dielectric fittings/unions. The installation of these
fittings is the responsibility of the installing contractor.
1. Connect the cold water inlet and hot water outlet to the appropriate connections as shown;
refer to the drawing for location and sizes.
2. Install in-line vacuum breaker and in-line pressure and temperature gauge, if supplied.
3. Install the combination temperature and pressure safety relief valve in the tapping provided.
Note that this is required by law for safety considerations.
12
Outlet to floor drain Install into provided tapping
Manual Release
Lever
Temperature and Pressure Relief Valve
4. Install a relief valve overflow pipe to a nearby floor drain. CAUTION: No valve of any type
should be installed between the relief valve and tank or in the drain line.
FILLING THE HEATER
1. Completely close the drain valve and open the highest hot water valve to allow all air to
escape from piping.
2. Open the valve to the cold water inlet and allow the heater and piping system to completely
fill, as indicated by a steady flow of water from the open faucet.
ELECTRICAL INSTALLATION
1. Enter electric enclosure with properly sized feeder leads (use 60° C copper wire for water
heaters rated less than 100 amps; otherwise use 75°C copper wire). Single-phase installations
require two (2) leads; three phase installations require three (3) leads.
2. Install these power leads into the box lugs on the terminal block or magnetic contactor.
3. Torque screws per torque chart included in Section VI.
4. All other electrical connections are made at the factory; therefore, no other electrical
connections are necessary.
FINAL CHECKS
1. Check all connections for tightness.
2. Ensure that all the above steps are completed.
3. After the water is heated for the first time, monitor the water temperature as described in
Section III, Quarterly Inspection.
Temperature Probe Temperature Probe
13
SECTION III - SCHEDULED MAINTENANCE AND OPERATION
WARNING / CAUTION
Before performing any maintenance procedure, make certain power supply is OFF and cannot
accidentally be turned on.
MAINTENANCE AND OPERATION
The heater is automatic in its operation. It will maintain water at the temperature setting of the
thermostat. The heater should not be turned on without first making sure that the vessel is full of
water and that all air has been released.
FREEZING
The vessel should be fully drained in the event the electricity has been turned off and if there is
danger of freezing.
QUARTERLY INSPECTION
1. Monitor thermostat
a. Let water heater completely heat to a designated thermostat setting.
b. After thermostat satisfies (that is, when the thermostat actually clicks off), draw water from
c. Compare water temperature of drawn water to the temperature setting of the thermostat when
d. If these two readings do not coincide within acceptable tolerances and verification has been
2. Lift test lever on relief valve and let water run through valve for a period of approximately 10
seconds. This will help flush away any sediment that might build up in water passageways.
3. Inspect element flange for leakage as follows:
a. Shut off Power Supply.
b. Remove element housing cover.
c. Visually inspect heating element gasket for evidence of leaks.
d. Rub finger around gasket that is between the heating element and tank flange for any
4. Check for loose electrical connections. Tighten as necessary.
heater.
it satisfies. Normal variation between the two points is approximately + 5°F.
made of the accuracy of the temperature-reading gauge, replace the thermostat.
evidence of moisture. If moisture is present or a water drip is observed, follow procedure
outlined in Section V.
14
Symptom Probable Cause Corrective Action / Remedy
No hot water
SECTION IV – TROUBLESHOOTING
Circuit breaker tripped at
source.
On/Off switch in ‘OFF’
position, if installed.
Circuit breaker at control
cabinet tripped, if installed.
Blown fuse in element fuse
block, if installed.
Blown fuse in transformer, if
installed.
High limit switch tripped. Reset high limit switch.
Loose wires. Tighten wires. Torque screws per
Heating element inoperable. Check heating element operation
Low line voltage. Have source electrical system
Faulty thermostat. Move thermostat dial through full
Faulty low water cut-off, if
installed.
Magnetic contactor does not
energize.
Reset circuit breaker.
Turn switch to ‘ON’ position.
Reset circuit breaker.
Replace fuse.
Replace fuse.
torque chart included in Section
VI.
by clamping an Amprobe around
each wire to the element. The
ampere reading should agree with
the nameplate ‘AMP’ figure.
checked by an electrician.
range. A definite ‘click’ should be
heard. If not, replace thermostat.
Check to see if tank is full of
water. If not, fill tank. If problem
continues and tank is full, check
for continuity between the
common and normally open
contact of the relay board. If
continuity is not observed, replace
low water cut-off.
Replace complete magnetic
contactor. Because of the design
of this particular contactor, it is
more desirable to replace complete
control rather than rebuilding coil,
contacts and springs, etc.
15
Water temperature below
settings at all times
Relief valve discharges
continuously
Faulty thermostat. Check thermostat adjustment.
Monitor thermostat as described in
Section III, Quarterly Inspection.
Replace if necessary.
Blown fuse in element fuse
block, if installed.
Heating element not working
on all phases
Heater improperly sized Verify heater is properly sized for
Excessive temperature or
pressure in tank
Replace fuse.
Check to see that heating element
is working on all phases, by
checking the resistance (ohms)
value for each element and
comparing with the chart included
in Section VI.
the flow rate and temperature rise
of your system. See formulas
included in Section VI. Replace
elements with proper size as
necessary.
Temperature and pressure relief
valves are made to operate if the
water temperature exceeds 210°F
or water pressure exceeds the
pressure rating of the safety relief
valve. If trouble is excessive
temperature, then thermostat is not
shutting off at the right setting and
thermostat must be replaced.
16
SECTION V - SERVICING & REPLACEMENT OF PARTS
WARNING / CAUTION
Before servicing or replacing any part make sure to turn the power supply switch to the OFF position.
MAGNETIC CONTACTOR
1. Disconnect power from unit.
2. Disconnect line and load wires to contactor.
3. Disconnect two (2) 14 gauge control circuit wires.
Control Wires
Line Wires
Load Wires
4. Loosen two (2) holding screws and remove contactor.
Mounting Screws
(Bottom screw not shown)
5. Replace with new contactor using reverse
procedure.
17
IMMERSION TEMPERATURE HIGH LIMIT CUT-OFF
1. Disconnect power from unit.
2. Remove access cover.
3. Remove high limit cover screw and cover.
Cover
Cover Screw
Reset Switch
4. Disconnect the two (2) 14 gauge wires.
Wires
Capillary Tube
5. Remove capillary tube and bulb from thermowell
6. Remove two (2) mounting screws.
Mounting Screws
7. Remove control and install new high limit switch by performing
above steps in reverse order. (Note: Be sure to place capillary tube into
slot in base prior to installing cover.)
18
IMMERSION THERMOSTAT
1. Disconnect power from unit.
2. Remove access cover and locate thermostat.
3. Remove high limit cover screw and cover.
Cover
Cover Screw
4. Disconnect the two (2) 14 gauge wires.
Wires
Capillary Tube
5. Remove capillary tube and bulb from thermowell.
6. Remove two (2) mounting screws.
Mounting Screws
7. Replace thermostat using reverse procedure. (Note: Be sure to
place capillary tube into slot in base prior to installing cover.)
19
HEATING ELEMENT
1. Disconnect power from unit.
2. Shut off incoming water supply.
3. Attach hose to drain connection.
4. Lift manual release lever on relief valve to let air into system or break union on outgoing
water line.
5. Drain water from tank.
6. Remove element housing cover
7. Disconnect the wires from the heating element terminals.
8. Disconnect conduit from coupling.
Conduit Coupling
Element Housing Cover
9. Remove nuts and bolts from flanges.
10. Withdraw element assembly and remove gasket.
Vessel Flange
Gasket
Flanged Element Assembly
11. Install new gasket and insert new
heating element.
12. Rewire element according to the voltage
and phase rating of the unit as shown
below.
13. Fill tank and check around gasket for any leaks.
20
RELIEF VALVE
1. Disconnect power from unit.
2. Shut off incoming water supply.
3. Lift test lever on relief valve to relieve pressure in tank.
4. Disconnect overflow piping.
5. Unscrew relief valve, remove assembly and replace with new one.
6. Connect overflow piping.
7. Turn on incoming water supply and check for leaks.
8. Turn safety switch to ON position.
Test Lever
Overflow Piping Outlet
Tank Connection
Temperature Probe
21
SECTION VI – MISCELLANEOUS CHARTS AND FORMULAS
NEMA ENCLOSURES
22
ELECTRICAL DATA
23
FORMULAS
24
TORQUE VALUES
BOLT SIZE
4-40
4-48 6.6 5.4 6.1 3.6 6.9 6.7
5-40 7.7 6.3 7.1 4.2 8.1 7.8
5-44 9.4 7.7 8.7 5.1 9.8 9.6
6-32 9.6 7.9 8.9 5.3 10.1 9.8
6-40 12.1 9.9 11.2 6.6 12.7 12.3
8-32 19.8 16.2 18.4 10.8 20.7 20.2
8-36 22.0 18.0 20.4 12.0 23.0 22.4
10-24 22.8 18.6 21.2 13.8 23.8 25.9
10-32 31.7 25.9 29.3 19.2 33.1 34.9
1/4-20 75.2 61.5 68.8 45.6 78.8 85.3
1/4-28 94.0 77.0 87.0 57.0 99.0 106.0
5/16-18 132 107 123 80 138 149
5/16-24 142 116 131 86 147 160
3/8-16 236 192 219 143 247 266
3/8-24 259 212 240 157 271 294
7/16-14 376 317 349 228 393 427
7/16-20 400 327 371 242 418 451
1/2-13 517 422 480 313 542 584
1/2-20 541 443 502 328 565 613
9/16-12 682 558 632 413 713 774
9/16-18 752 615 697 456 787 855
5/8-11 1110 907 1030 715 1160 1330
5/8-18 1244 1016 1154 798 1301 1482
3/4-10 1530 1249 1416 980 1582 1832
3/4-16 1490 1220 1382 958 1558 1790
7/8-9 2328 1905 2140 1495 2430 2775
7/8-14 2318 1895 2130 1490 2420 2755
1-8 3440 2815 3185 2205 3595 4130
1-14 3110 2545 2885 1995 3250 3730
18-8 S/S
IN.-LBS.
5.2 4.3 4.8 2.9 5.5 5.3
BRASS
IN.-LBS.
SILICON
BRONZE
IN.-LBS.
ALUMINUM
2024-T4
IN.-LBS.
316 S/S
IN.-LBS.
MONEL
IN.-LBS.
25
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