Hubbell CR User Manual

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: [phone]
FAX: [phone]

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.

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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

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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.

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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

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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.

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