Hubbell CR User Manual

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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°Ffor 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

3

4

SECTION I - GENERAL DESCRIPTION AND CONSTRUCTION

GENERAL DESCRIPTION

This book describes a packaged electric heater that is a stationary, self-containedunit. 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-FerrousVessel Materials:

1.Copper-Silicon– Acopper-siliconalloy 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 tocopper-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.

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OUTER SHELL, INSULATION, AND SUPPORTS

The pressure vessel is encapsulated in 2-inchesofhigh-densityfiberglass insulation. The protective shell is constructed of galvaneel and is coated with a durable silver hammertone finish. The horizontal configuration is supported onheavy-dutysteelI-beamsupports. 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-proofenclosure 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-stageimmersion thermostatic switch. As an optional any of the following may be supplied; afour-stageimmersion thermostatic switch, asolid-statestaging controller with thermistor, or a digital 1/16 DIN temperature controller with thermocouple. See drawing for specific details. Thesingle-stageimmersion thermostat can be adjusted through a range of 100° - 190° F. A low range, (30° - 110° F), operating thermostat is also available in thesingle-stageversion. Thefour-stageimmersion thermostat can be adjusted through a range of 100° - 250° F and is capable of switching four circuits. Thesolid-statestaging controller automatically bringson-linethe 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 thesingle-stageimmersion thermostat.

Single-StageImmersion Thermostat

Four-StageImmersion 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-offswitch 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 ahigh-limit.

Manual Reset

MAGNETIC CONTACTOR

The magnetic contactor(s) is a heavy-dutyresistive 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-voltfor safety when working with control circuits.

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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-voltor type JJS for voltage less than600-volt.

Type JJS

Type NON

LOW WATER CUT-OFF

Used as a safety device, the electronic low water cut-offis used to detect a low water situation and disengage the operating coils in the magnetic contactor(s). Once the condition is remedied, the low watercut-offswitch is automatically reset.

Conductive Type Low Water Cut-OffRelay

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.

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On / Off Control Switch

A built-innon-fusedOn/Off disconnect switch may be supplied with the control panel to decrease the risk of injury when working with the control panel.

Built-InCircuit Breaker

A built-incircuit 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.

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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-inchdial may be supplied forin-lineinstallation (shipped loose) or factory installed in the tank.

Special Customized Features

Please reference drawing for details.

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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. ANSIZ21.22-1971.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-linevacuum breaker andin-linepressure 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.

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Outlet to floor drain

Install into provided tapping

Manual Release

Lever

Temperature Probe

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-phaseinstallations 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.

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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 heater.

c.Compare water temperature of drawn water to the temperature setting of the thermostat when it satisfies. Normal variation between the two points is approximately + 5°F.

d.If these two readings do not coincide within acceptable tolerances and verification has been made of the accuracy of the temperature-readinggauge, replace the thermostat.

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 evidence of moisture. If moisture is present or a water drip is observed, follow procedure outlined in Section V.

4.Check for loose electrical connections. Tighten as necessary.

14

SECTION IV – TROUBLESHOOTING

Symptom

Probable Cause

Corrective Action / Remedy

No hot water

Circuit breaker tripped at

Reset circuit breaker.

 

source.

 

 

On/Off switch in ‘OFF’

Turn switch to ‘ON’ position.

 

position, if installed.

 

 

Circuit breaker at control

Reset circuit breaker.

 

cabinet tripped, if installed.

 

 

Blown fuse in element fuse

Replace fuse.

 

block, if installed.

 

 

Blown fuse in transformer, if

Replace fuse.

 

installed.

 

 

High limit switch tripped.

Reset high limit switch.

 

 

 

 

Loose wires.

Tighten wires. Torque screws per

 

 

torque chart included in Section

 

 

VI.

 

Heating element inoperable.

Check heating element operation

 

 

by clamping an Amprobe around

 

 

each wire to the element. The

 

 

ampere reading should agree with

 

 

the nameplate ‘AMP’ figure.

 

Low line voltage.

Have source electrical system

 

 

checked by an electrician.

 

Faulty thermostat.

Move thermostat dial through full

 

 

range. A definite ‘click’ should be

 

 

heard. If not, replace thermostat.

 

Faulty low water cut-off,if

Check to see if tank is full of

 

installed.

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.

 

Magnetic contactor does not

Replace complete magnetic

 

energize.

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

Faulty thermostat.

Check thermostat adjustment.

settings at all times

 

Monitor thermostat as described in

 

 

Section III, Quarterly Inspection.

 

 

Replace if necessary.

 

Blown fuse in element fuse

Replace fuse.

 

block, if installed.

 

 

Heating element not working

Check to see that heating element

 

on all phases

is working on all phases, by

 

 

checking the resistance (ohms)

 

 

value for each element and

 

 

comparing with the chart included

 

 

in Section VI.

 

Heater improperly sized

Verify heater is properly sized for

 

 

the flow rate and temperature rise

 

 

of your system. See formulas

 

 

included in Section VI. Replace

 

 

elements with proper size as

 

 

necessary.

Relief valve discharges

Excessive temperature or

Temperature and pressure relief

continuously

pressure in tank

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.

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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.)

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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.)

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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.

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