Bird Technologies 8630B User Manual

INSTRUCTION BOOK

MODULOAD

SERIES 8630 AND 8630B

®

RF LOAD RESISTOR

Bird® Electronic Corporation
30303 Aurora Road
Cleveland (Solon), Ohio 44139

Sales & Technical Support: 440-248-1200

Sales email: [e-mail]

Technical Support email: [e-mail]

Moduload

866-695-4569 toll free

©Copyright 2006 by Bird Electronic Corporation

Instruction Book P/N 920-8630S Rev. G

®

, Econoload®, Econoline®, and Thruline® are

registered trademarks of Bird Electronic Corporation

I am not blank

Safety Precautions

The following are general safety precautions that are not necessarily
related to any specific part or procedure and do not necessarily appear
elsewhere in this publication. These precautions must be thoroughly
understood and applied to all phases of operation and maintenance.

Keep Away From Live Circuits

Operating personnel must at all times observe normal safety regulations.
Do not replace components or make adjustments inside the equipment
with high voltage turned on. To avoid casualties, always remove power.

Shock Hazard

Do not attempt to remove the RF transmission line while RF power is
present.

Do Not Service Or Adjust Alone

Under no circumstances should any personnel reach into an enclosure for
the purpose of service or adjustment of equipment except in the presence
of someone who is capable of rendering aid.

Safety Earth Ground

An uninterruptible earth safety ground must be supplied from the main
power source to test instruments. Grounding one conductor of a two
conductor power cable is not sufficient protection. Serious injury or death
can occur if this grounding is not properly supplied.

Chemical Hazard

Dry cleaning solvents for cleaning parts may be potentially dangerous.
Avoid inhalation of fumes or prolonged contact with skin.

Resuscitation

Personnel working with or near high voltages should be familiar with
modern methods of resuscitation.

i

Bird 8630B Series Moduload RF Load Resistor

Safety Symbols

Warning notes call attention to a procedure, which if not correctly

performed, could result in personal injury.

Caution notes call attention to a procedure, which if not correctly

performed, could result in damage to the instrument.

This symbol indicates that a shock hazard exists if the
precautions in the instruction manual are not followed.

The caution symbol appears on the equipment indicating
there is important information in the instruction manual
regarding that particular area.

WARNING

CAUTION

This symbol indicates that the unit radiates heat and
should not be touched while hot.

 NOTE: Calls attention to supplemental information.

Warning Statements

The following safety warnings appear in the text where there is danger to
operating and maintenance personnel and are repeated here for emphasis.

WARNING

Never attempt to connect or disconnect RF equipment from the

transmission line while RF power is being applied.

Leaking RF energy is a potential health hazard.

WARNING

Ethylene glycol is a toxic material. Do not take internally. Avoid eye

contact. Inhaling the vapors may be irritating to the lungs.

Caution Statements

The following equipment cautions appear in the text whenever the
equipment is in danger of damage and are repeated here for emphasis.

CAUTION

This equipment is designed for operation in a horizontal position only,

with mounting brackets down. Do not operate in any other manner.

ii

CAUTION

Before any RF operation of the load is attempted, the transmitter

interlock and ac line attachment to the equipment must be made. First

attach the transmitter interlock connections to the two binding posts on

the front panel and then connect the power cable.

CAUTION

The 115 V or 230 Vac line may be connected, but the ac power must not

be turned on unless coolant is in the system and filled to the correct

level. Damage to the pump will result otherwise.

CAUTION

Operation without sufficient coolant can damage the unit.

CAUTION

Do not use any sealant, leak-stopping material, or automotive antifreeze

in the coolant. Use only distilled water and pure ethylene glycol.

CAUTION

Do not attempt to alter the flow switch setting or disturb the coolant pump.

CAUTION

Do not operate the load without connecting the interlock. Even

momentary application of power to the load while the cooling

circulation is off, or possibly functioning improperly, will cause almost

immediate destruction of the resistor element.

CAUTION

Do not apply more than the rated RF power to the load. Excessive RF

power will damage the load resistor.

CAUTION

Do not block air flow. Air enters the housing through the circular fan

openings and exhausts through the grille opposite.

CAUTION

Do not disconnect the line power first. Even a momentary application of

RF power to the load while the cooling circulation is off will cause

almost immediate destruction of the resistor element.

iii

Bird 8630B Series Moduload RF Load Resistor

CAUTION

Do not remove any fittings from the water chamber. The elbows could

be damaged, and it may be difficult to restore them to their original

positions while keeping a water-tight seal. Check the switch for free

operation. Flush and clean with mild detergent if necessary, and rinse

thoroughly in clear water

CAUTION
Before storing the unit, follow the storage instructions in the Storage
section of the Maintenance chapter. Failure to follow the instructions

may result in damage to the unit.

CAUTION

Before shipping the unit, follow the shipping instructions in the

Maintenance chapter. Failure to properly prepare the unit for shipping

may result in damage to the unit.

iv

Safety Statements

USAGE
ANY USE OF THIS INSTRUMENT IN A MANNER NOT

SPECIFIED BY THE MANUFACTURER MAY IMPAIR THE

INSTRUMENT’S SAFETY PROTECTION.
USO
EL USO DE ESTE INSTRUMENTO DE MANERA NO ESPECIFICADA

POR EL FABRICANTE, PUEDE ANULAR LA PROTECCIÓN DE
SEGURIDAD DEL INSTRUMENTO.

BENUTZUNG
WIRD DAS GERÄT AUF ANDERE WEISE VERWENDET ALS VOM

HERSTELLER BESCHRIEBEN, KANN DIE GERÄTESICHERHEIT
BEEINTRÄCHTIGT WERDEN.

UTILISATION
TOUTE UTILISATION DE CET INSTRUMENT QUI N’EST PAS

EXPLICITEMENT PRÉVUE PAR LE FABRICANT PEUT
ENDOMMAGER LE DISPOSITIF DE PROTECTION DE
L’INSTRUMENT.

IMPIEGO
QUALORA QUESTO STRUMENTO VENISSE UTILIZZATO IN MODO

DIVERSO DA COME SPECIFICATO DAL PRODUTTORE LA
PROZIONE DI SICUREZZA POTREBBE VENIRNE COMPROMESSA.

SERVICE
SERVICING INSTRUCTIONS ARE FOR USE BY SERVICE -

TRAINED PERSONNEL ONLY. TO AVOID DANGEROUS
ELECTRIC SHOCK, DO NOT PERFORM ANY SERVICING UNLESS
QUALIFIED TO DO SO.

SERVICIO
LAS INSTRUCCIONES DE SERVICIO SON PARA USO EXCLUSIVO

DEL PERSONAL DE SERVICIO CAPACITADO. PARA EVITAR EL
PELIGRO DE DESCARGAS ELÉCTRICAS, NO REALICE NINGÚN
SERVICIO A MENOS QUE ESTÉ CAPACITADO PARA HACERIO.

v

Bird 8630B Series Moduload RF Load Resistor

WARTUNG
ANWEISUNGEN FÜR DIE WARTUNG DES GERÄTES GELTEN NUR

FÜR GESCHULTES FACHPERSONAL.
ZUR VERMEIDUNG GEFÄHRLICHE, ELEKTRISCHE SCHOCKS,

SIND WARTUNGSARBEITEN AUSSCHLIEßLICH VON
QUALIFIZIERTEM SERVICEPERSONAL DURCHZUFÜHREN.

ENTRENTIEN
L’EMPLOI DES INSTRUCTIONS D’ENTRETIEN DOIT ÊTRE

RÉSERVÉ AU PERSONNEL FORMÉ AUX OPÉRATIONS
D’ENTRETIEN. POUR PRÉVENIR UN CHOC ÉLECTRIQUE
DANGEREUX, NE PAS EFFECTUER D’ENTRETIEN SI L’ON N’A PAS
ÉTÉ QUALIFIÉ POUR CE FAIRE.

ASSISTENZA TECNICA
LE ISTRUZIONI RELATIVE ALL’ASSISTENZA SONO PREVISTE

ESCLUSIVAMENTE PER IL PERSONALE OPPORTUNAMENTE
ADDESTRATO. PER EVITARE PERICOLOSE SCOSSE ELETTRICHE
NON EFFETTUARRE ALCUNA RIPARAZIONE A MENO CHE
QUALIFICATI A FARLA.

vi

About This Manual

This instruction book covers the 8630B Series Moduload RF Load
Resistors, which specificaly covers the models listed below:

8631-115 8631-115-5-N 8635-115-5 8638-115 8638-230-6
8631-230 8631-230-6-N 8635-230-6 8638-230 8638-115-5-N
8631-115-5 8635-115 8635-115-5-N 8638-115-5 8638-230-6-N
8631-230-6 8635-230 8635-230-6-N

8631B-115 8635B-115-5 8638B-115
8631B-230 8635B-230-6 8638B-230
8631B-115-5 8635B-115 8638B-230-6
8631B-230-6 8635B-230 8638B-115-5

This instruction book is arranged so that essential information on safety
is in the front of the book. Reading the Safety Precautions before
operating the equipment is strongly advised. The remainder of this
instruction book is divided into Chapters and Sections.

Operation

First time operators should read Chapter 1 - Introduction, Chapter 2 ­Theory of Operation, and Chapter 3 - Installation to get an overview of
equipment capabilities and how to install it. An experienced operator can
refer to Chapter 4 - Operating Instructions. All instructions necessary to
operate the equipment are contained in this chapter.

Maintenance

All personnel should be familiar with preventative maintenance found in
Chapter 5 - Maintenance. If a failure should occur, the trouble-shooting
section will aid in isolating and repairing the failure. Parts lists and
repair instructions are also in this chapter.

Changes To The Manual

We have made every effort to ensure this manual is accurate at the time
of publication. If you should discover any errors or if you have suggestions

vii

Bird 8630B Series Moduload RF Load Resistor

for improving this manual, please send your comment to our factory. This
manual may be periodically updated. When inquiring about updates to
this manual, refer to the part number and revision level on the title page.

viii

Naming Conventions

The following terms will be used throughout this manual to refer to certain
components of the Moduload:

Moduload: The entire unit.

Load: The component which connects to the RF line. It is connected to the HEAT

EXCHANGER with two hoses. It contains the RESISTOR.

Heat Exchanger: The component containing the pump, blower, coolant

reservoir, control panel, and electrical access box. It is connected to the LOAD
with two hoses.

Resistor: A subcomponent of the LOAD. This is the ceramic resistor which

actually absorbs the RF power.

ix

Bird 8630B Series Moduload RF Load Resistor

x

Table of Contents

Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . i

About This Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Purpose and Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Performance Characteristics and Capabilities . . . . . . . . . . . . . . . . . . . . . . . 1

Dimensions and Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Power and Utility Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Environmental Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Items Supplied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Items Required but not Supplied. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Tools and Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Optional Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Heat Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Flow Interlock Control Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Unpacking and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Site and Shelter Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Filling Coolant Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Blower Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

DC Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Interlock Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

AC Line Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Connecting RF Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Model 8631 and 8631B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Model 8635 and 8635B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Model 8638 and 8638B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

xi

Preliminary Equipment Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Meter Rack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . 15

Use and Function of Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Initial Adjustments and Control Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Equipment Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Normal Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Emergency Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Performance Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Radiator Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Connector and Outside . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

General Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Measure Load DC Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Water Flow Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Routine Service Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Flushing the System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

RF Load Resistor Unit Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Pump/Motor Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Water Flow Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Time Delay Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Replace Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Load Resistor Internal Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Resistor Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Resistor Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Replacement of Fractured Resistor or Damaged Internal Parts. . . . . . . . . . . . 31

Resistor Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Input Center Conductor Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Final Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

xii

Storage and Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

xiii

xiv

Chapter 1 Introduction

This publication refers to the Moduload RF Load Resistor Series 8630
and 8630B. The differences between models are listed in the
specifications. All models will generally be referred to as a load
throughout this manual.

The information in this instruction book pertains to all models except
noted differences referred to in the text.

This chapter contains intoductory information including items
supplied, items required, unpacking, inspecting, and the
specifications.

Purpose and

Function

Performance

Characteristics

and Capabilities

The Bird Moduload Loads are self-cooling, low reflection, non­radiating terminations for high power 50 ohm RF transmission lines.

They are for use on CW, AM, FM, SSB, and TV modulation envelopes,
and within certain limits on radar or pulse modes. Information for
use involving pulse type signals should be obtained directly from Bird
Electronic Corporation.

The 8630 and 8630B series Loads are capable of continuous power
dissipation of 10 kW with a voltage standing wave ratio (VSWR) of
less than 1.1 to 1.0 from 1 kHz to 1000 MHz. The respective models
provide direct connection to 3-1/8 inch and 1-5/8 inch 50 ohm coaxial
lines.

The equipment consists of three basic systems: the RF load assembly,
the control system, and the heat exchanger system. The load
assembly contains the resistor element with its internal water cooling
system. The control system includes the electrical circuitry required
to prevent damage to the transmitter in case of malfunction of the
load, and to protect the RF load should the water flow slow down. The
heat exchanger components consist essentially of the pump/motor, the
side blower, the coolant collector tank, and a finned cooling coil unit
opposite the blower.

When used in conjunction with the appropriate Bird Model Thruline
Wattmeter, such as those in the 4600A, 4800A or 4712 series, the
Moduload Coaxial Load may be used for direct RF power
measurements within the equipment ratings.

1

Bird 8630B Series Moduload RF Load Resistor

Dimensions and

Weight

Power and Utility

Requirements

Environmental

Requirements

The 8630 and 8630B Series load is 22-1/8 inches long, exclusive of the
connector, 15-13/16 inches wide, and 15-15/16 inches high (562 x 402
x 405 mm). Its net weight, filled with 100 percent water as coolant, is
113 lb (51.3 kg) and the shipping weight is 125 lb (56.7 kg).

The 8630 and 8630B Series loads are offered in four standard forms
which differ in the ac input power requirements.

y -115 for 115 V, 60 Hz, 9 Amp, single phase.
y -230 for 230 V, 50 Hz, 4.5 Amp, single phase.
y -115-5 for 115 V, 50 Hz, 9 Amp, single phase.
y -230-6 for 230 V, 60 Hz, 4.5 Amp, single phase.

The 8630 and 8630B Series loads are not intended for use outdoors
where they would be exposed to the elements. They should be used
indoors in a clean, dry, dust and vibration-free environment. The
ambient temperature range is determined by the coolant. For 100
percent water the range is +5°C to +45°C (+41°F to +113°F). For a
mixture of 65 percent water and 35 percent ethylene glycol the range
is -20°C to +35°C (-4°F to +95°F).

It is important that the room temperature remain within these limits
for proper operation of the unit, otherwise a derating of its load value
will be necessary. To avoid this derating, it may be necessary to
arrange for venting of the air flow from the load to the outside.
Consult Bird Electronic Corporation for more details.

Items Supplied The 8630 and 8630B Series loads are equipped with standard RF

connectors.

y Model 8630 and 8631B — 3-1/8 inch EIA flanged connector.
y Model 8630 and 8635B — 1-5/8 inch EIA flanged connector.
y Model 8630 and 8638B — 3-1/8 inch unflanged connector.

They are supplied with a container of ethylene glycol, for making the
coolant mixture, when ordered.

Items Required but

not Supplied

The required items are:

y A mating connector on the coaxial transmission line.
y A conveniently located ac power receptacle to plug in the power

cable.

y Distilled water for coolant, or coolant mixture.

2

Tools and Test

Equipment

Only simple tools such as screwdrivers and wrenches are needed for
disassembling a Moduload load resistor. A multimeter or an
ohmmeter with an accuracy of 1 percent or better at 50 ohms is
suggested for checking the DC resistance of the RF load resistor. A
basic VOM will suffice for checking the rest of the circuitry.

Optional Items Dolly, P/N 6771-011 — For ease in moving the load. Consult Bird

Electronic Corporation for more information.

3

Bird 8630B Series Moduload RF Load Resistor

Figure 1

Bird 8630 and

8630B Series

Outline Drawing

GENERANT

NOMINAL

20-5/16 (516mm)

22-1/8 (562mm)

21-5/16 (541mm)

10' AC CABLE

PROVIDED

(405mm)

15-15/16

VENT PLUG

FILLER PLUG

R.F.LOAD

3-1/8" FLANGED

3-1/2

(89mm)

(402mm)

15-13/16

AIR

FLOW

29/32 (23mm)

GENERANT

7-29/32 (201mm)

NOMINAL

15-13/16 (402mm)

AC ON

INTERLOCK

230VAC 8AMP

60Hz 3AB

3/32

14"

SEE DETAIL FOR (4)

(356mm)

MOUNTING HOLES

FREQUENCY RANGE 1KHz-1GH z

WATTS 10,000 OHMS 50

MODEL 8631-230-6 SERIAL

1 PHASE 60Hz 4.5 AMPS

AC LINE SUPPLY 230 VOLTS

CAUTION

(2.4mm)

3/8

(10mm)

DETAIL: FULL SCALE

4

Chapter 2 Theory of Operation

The 8730 Series style Econoload Coaxial load resistor installed in this
unit is unique in having its water supply primarily directed over the
outer, wet film type, resistive coating of the substrate. This
eliminates the need for an intermediate heat transfer system,
reducing the load size to a minimum. The absence of intermediate
cooling fluids considerably simplifies the construction and sealing of
this unit. It can be readily disassembled in the field for resistor
element replacement (refer to the Chapter 5 - Maintenance).

Heat Transfer The 50 ohm resistor consists of a substrate which has a permanently

deposited resistive film, covered by a thin layer of electrically
nonconductive material. The heat generated by the absorped RF
power is transferred from the film to the water which flows over it
through a restricted chamber surrounding the resistor body. This
water, first carried to the front of the load resistor, passes over the
entire length of the resistor and discharges through the sealed water
chamber at the rear. The composite dielectric characteristics and the
distinctive design of these enclosures provide an accurate 50 ohm
termination over the specified frequency range of this load - 1 kHz to
1000 MHz.

Flow Interlock

Control Circuit

The interlock control circuit provides instantaneous fail-safe
protection of the transmitter and Moduload in the event of even
momentary interruption of the coolant supply. This protection is
necessary because dissipation of the heat generated by the RF power
is critically dependent on a required minimum water flow of 2.5
gallons (9.5 liters) per minute at all times, regardless of the coolant
temperature.

CAUTION

Do not attempt to alter the flow switch setting or disturb the

coolant pump.

The water flow switch, installed directly on the coolant input line to
the load resistor, is a “normally open” type; i.e. its electrical contacts
open when deactivated. Closed during equipment operation, the
switch is adjusted to open when the coolant flow drops below the
minimum. When the water flow switch contacts open, the time delay
switch is deactivated, which at once opens the interlock switch,
causing immediate transmitter shutdown. Also, the centrifugal
impeller of the pump is carefully selected for the necessary flow rate.

5

Bird 8630B Series Moduload RF Load Resistor

The proper operation of this equipment depends on these conditions
being maintained.

The time delay relay keeps the interlock switch open for a
predetermined interval (set at about 2 seconds, nominal), to allow the
minimum flow of 2.5 gallons per minute to be established. This
safeguard feature ensures proper operation of the cooling system
before RF power is applied to the load, preventing resistor damage or
burnout. As an additional safeguard, an over temperature
thermoswitch, normally closed at or below +85°C (+185°F) for the
8630 series and at or below +79°C (+174°F) for the 8630B series, is
wired in series with the flow switch for protection from overheating
due to overloading of the load.

6

Chapter 3 Installation

This chapter provides information for on-site requirements,
unpacking, inspection, and preparing the load for use.

CAUTION

This equipment is designed for operation in a horizontal position only,

with mounting brackets down. Do not operate in any other manner.

The 8630 and 8630B series load is to be installed, and operated, in a
horizontal position. The unit is shipped horizontal, and normally
stands on its attached base brackets.

Unpacking and

Inspection

Site and Shelter

Requirements

Mounting

1. Carefully inspect the shipping container for signs of damage. If
damage is noticed, do not unpack the unit. Immediately notify the
shipping carrier and Bird Electronic Corporation.

2. If the container is not damaged, unpack the unit. Save the packing
materials in case the unit should need to be shipped again.

3. Inspect all of the components for visible signs of damage.
Immediately notify the shipping carrier and Bird Electronic
Corporation of equipment damage or missing parts.

The load may be operated anywhere that adequate ac line power and
ventilation are available, and ambient temperatures do not exceed
those given in the specifications.

 Note: 10 kW being equivalent to 34,000 Btu/h (8568 kilogram- calories/

hr), a sufficient quantity of air must be provided. Allow room for
unobstructed air intake on the side facing the fan grille, and a clearance
of two or three feet beyond the grille outlet opposite.

For installation of the equipment, mounting angle brackets are
attached to the front, and back edges of the enclosure. They may be
removed by unscrewing the four 8-32 Phillip Truss head screws
holding each bracket. These brackets have two slots each on the 14" x
21-15/16" (356 x 557 mm) centers to accommodate four 1/4" screws
that may be used for mounting the unit.

Coolant

Before shipment, the Moduload is drained of coolant to avoid possible
damage in transit from freezing. The system must be refilled with
coolant before it can be put into operation. The unit operates with 10

7

Bird 8630B Series Moduload RF Load Resistor

pints (4.74 liter) of coolant. The coolant must be either; distilled water
or a mixture of distilled water and ethylene glycol.

Ethylene glycol is toxic. Do not take internally. Avoid contact with

eyes, skin, and clothing. Avoid breathing vapor. Wash thoroughly

Use only distilled water or the supplied ethylene glycol as coolant.

Do not use tap water, automotive antifreeze, sealants, or leak

stopping material. Use of these materials will damage the

Distilled water is the primary coolant for the Bird 8630 and 8630B.
Ethylene glycol should be added to prevent bacterial growth and
freezing; 10% – 35% ethylene glycol is recommended. Using at least
10% will prevent bacteria growth and 35% will protect against
freezing to –20°C.

WARNING

after handling.

CAUTION

instrument and void all warranties.

Filling Coolant

Reservoir

Figures 3 and 4 shows the coolant’s freezing point for a given
percentage of ethylene glycol in the mix. The following example shows
the weights to make a 65% distilled water to 35% ethylene glycol
mixture in 1 and 5 gallon quantities.

Ingredient 1 Gal. (3.78 L) 5 Gal. (18.9 L)
Distilled Water
Ethylene Glycol

5.6 lb (2.54 kg) 28.0 lb (12.7 kg)

3.0 lb (1.39 kg) 15.2 lb (6.9 kg)

The load’s electrical and thermal performance is impaired by
impurities or additives in the coolant. Impurities which accumulate
as scale on the resistor surface are especially damaging. Only use
distilled water or a mixture of distilled water and ethylene glycol as
coolant. To ensure proper mixing add the water first, then the
ethylene glycol.

The Bird 8630 and 8630B has a coolant capacity of about 10 pints
(4.74 liter). To fill the coolant, follow these steps:

CAUTION

Operation without sufficient coolant can damage the unit.

1. Make sure the drain plug is in place. Check that the hose
connections are correct and properly tightened.

2. Remove the filler cap on top of the unit.

8

Installation

3. Pour approximately 4 pints (2.0 Liters) of coolant in the unit.

4. Turn on the motor, for only a few seconds, to pull the liquid into
the system and draw the coolant level down to the bottom of the
tank. Do not run the pump too long, as partially dry operation may
damage its mechanism.

 Note: A convenientt method is to watch the coolant level through

the reservoir filler. Stop the pump when the coolant level
approaches the bottom of the tank.

5. Repeat filling in the above manner twice more, with about 3 pints
(1.5 liters) each time, or until the fluid remains steady at the
proper level. The unit should be full to a level of about 2-7/8 inches
(73 mm) below the top face of the filler tube opening, or to the high
mark on the gauge. Add coolant if necessary to bring to the
required level.

6. Run the unit for about five minutes to remove any trapped air in
the system.

7. Recheck the fluid level before applying RF power.

 Note: The filler plug is equipped with a breather vent to relieve internal

pressure caused by the heated coolant. It is normally closed, but is set to
open at 2 lb/in
impurities or other chemical additives in the cooling liquid. Therefore,
the cooling liquid should be distilled water, with pure industrial grade
ethylene glycol added if required, and should be kept clean at all times.

Introducing contaminates from unsuitable coolant liquids could coat
the cooling system components, particularly the resistor surface. This
would unfavorably affect the thermal performance and VSWR of the
load. When this is suspected always check the VSWR. General scale
accumulation is not likely unless the load resistor is used outside the
unit, with an improper water supply. If the coolant system has been
contaminated, flush it out according to the instructions in the
Maintenance Chapter.

Blower Fan The fan is wired direct to the ac line input and will always operate

along with the pump when the ac line power is turned on.

DC Resistance Before the unit is put into operation, check the DC resistance. Refer

to the Maintenance chapter for complete details and instructions.

2

. The electrical performance of the load is affected by

9

Bird 8630B Series Moduload RF Load Resistor

0

y

0

C

0

Figure 2

4

Freezing Point of

Ethylene Glycol /
Water Mixture °F

20

0

-20

-40

Specifications for ethylene glycol

Temperature, Degrees Fahrenheit

-60
having: specific gravity 1.125 @

32°F; specific heat .575 @ 68°F

-80

10 20 30 40 50 60

% Eth

lene Glycol

Figure 3

Freezing Point of

Ethylene Glycol /

Water Mixture °C

-10

-20

elsius

-30

-40

Temperature, Degrees

Specifications for ethylene glycol

-50
having: specific gravity 1.125 @

32°F; specific heat .575 @ 68°F

-60

10 20 30 40 50 6

% Ethylene Glycol

10

Installation

Interlock

Connections

AC Line

Attachment

A terminal strip provides connection to the transmitter’s internal
safety interlock circuitry. An active interlock state occurs as a result
of either high coolant temperature or no coolant flow. It will also be
active for about 2 seconds after power up.

Interlock connections are made to the terminal strip on the front of
the unit.

1. Use number 22 AWG (or heavier) wire for interlock connections.
Attach solderless ring terminals to the wire ends to ensure safe
operation, and to ease installation.

2. Connect the interlock wires to the interlock terminal strip as
required for the transmitter in use.

CAUTION
Before any RF operation of the load is attempted, the transmitter
interlock and ac line attachment to the equipment must be made.

First attach the transmitter interlock connec tions to the two

binding posts on the front panel and then connect the power cable.

CAUTION

The 115 V or 230 Vac line may be connected, but the ac power must

not be turned on unless coolant is in the system and filled to the

correct level. Damage to the pump will result otherwise.

Before applying ac power to the unit, make sure:

y Coolant is in the system.
y Coolant is filled to the correct level.
y The green wire at the supply end is fastened to ground.

The ac power supply may be either 115 or 230 V depending on the
unit requirements. AC line power is supplied to the 3-wire ac panel
module socket by means of the 10 foot cable and matching socket that
is furnished with the equipment. The third wire in the cable, coded
green, is the ground. For proper protection, if a 3-wire type plug and
outlet is not used, fasten the green wire at the supply end to a
satisfactory ground.

11

Bird 8630B Series Moduload RF Load Resistor

Connecting RF Power

After installing the load, the RF transmission line can be attached
using standard coaxial line coupling kits.

Never attempt to connect or disconnect RF equipment from the

transmission line while RF power is being applied.

Connect the coaxial RF transmission line to the unit. For the
respective 8630 and 8630B Series models the connections are as
follows:

WARNING

Leaking RF energy is a potential health hazard.

Model 8631 and

8631B

Model 8631 and 8631B - 3-1/8" EIA, 50 ohm, swivel flanged. Refer to
Figure 4 while following the instructions below.

1. Use 3-1/8" EIA Coupling Kit, Bird P/N 4600-020, which includes
six 3/8-16 x 1-1/2" bolt and nut sets, O-Ring, and insulated center
bullet.

2. Insert the center bullet, push into seat insulator in facing, and
install the O-Ring in the groove if required.

3. Connect the coaxial input in a straight line, push in carefully to
close. The swivel flange on the load makes connection independent
of a fixed flange on the coaxial input line.

4. Insert bolt sets around the flange connection, and tighten evenly.

Figure 4

Connecting RF

Power Model 8631

and 8631B

RF Coaxial Line 3/8-16 x 1-1/2 Bolt Bullet RF Load Connector

Model 8635 and

12

8635B

Model 8635 and 8635B - 1-5/8" EIA Coupling Kit, Bird P/N 4712-020,
which includes four 5/16-18 x 1-1/2" large bolt and nut sets, O-Ring,
and anchor bullet. The assembly procedure is the same as for Model
8631 and 8631B. Refer to the paragraph Connecting RF Power ­Model 8631 and 8631B, above.

Installation

Model 8638 and

8638B

Model 8638 and 8638B - 3-1/8" unflanged, 50 ohm impedance. Refer
to Figure 5 while following the instructions below.

1. Use the Bird Coupling Kit P/N 5-726, consisting of two clamping
bands, an outer sleeve, and the center conductor coupling bullet.

2. Insert the center bullet, and bottom it on the midpoint nibs.

3. Position the outer sleeve, with clamps, over the input connector.

4. Introduce the transmission line and seat snugly against the
coupling stops.

5. Position clamp bands evenly about 1-3/4" apart, and tighten.

Figure 5

Connecting RF

Power Model 8638

and 8638B

RF Coaxial Line Clamping Bands Connector Sleeve Bullet RF Load Connector

Preliminary

Equipment Check

Meter Rack The Meter Rack is used to hold the meter at the correct angle, for the

Check the RF load for acceptable electrical condition. Refer to the
Maintenance Chapter for the procedure to determine load impedance.
Below is the test equipment needed, and the critical parameters.

Equipment Needed: Digital Multimeter

Accuracy: 1 percent at 50 ohms, ± 1 digit

best possible viewing. Assemble and install as instructed below:

1. Assemble the kit using #6-32 x 1/4 screws, (supplied).

2. Remove the 2 screws from the panel at a desired mounting
location.

3. Mount the assembled Meter Rack using #8-32 x 3/8 phillips truss
(supplied). Refer to Figure 6.

13

Bird 8630B Series Moduload RF Load Resistor

Figure 6

Meter Rack

Assembly

14

Operating Instructions

Chapter 4 Operating Instructions

CAUTION

Do not operate the load without proper coolant levels. Operation without

sufficient coolant can damage the unit.

Use and Function

of Controls

Initial Adjustments

and Control

Settings

Equipment Startup

The Series 8630 and 8630B loads have no operating controls, other
than the ON/OFF switch; therefore, they do not require an operator
in attendance. The 8630 series is equipped with two indicators. One is
a pilot light in the ON/OFF switch, to warn that the ac power is being
applied. The other is the coolant level gauge, referred to in Chapter 3

- Installation. The 8630B series is equipped with one indicator which

is the coolant level gauge, referred to in Chapter 3 - Installation.

There are no adjustments or settings required beyond confirming that
the cooling system contains an adequate level of coolant for proper
operation. Refer to Chapter 3 - Installation.

WARNING

Never attempt to connect or disconnect an RF cable while power is

on at the RF power source. Radiated RF energy is a potential health

hazard.

CAUTION

Do not apply more than the rated RF power to the load. Excessive

RF power will damage the load resistor.

CAUTION

Do not block air flow. Air enters the housing through the circular

fan openings and exhausts through the grille opposite.

CAUTION

Do not operate the load without connecting the interlock. Even

momentary application of power to the load while the cooling

circulation is off, or possibly functioning improperly, will cause

almost immediate destruction of the resistor element.

1. Make sure coolant level is adequate, and verify fan operation.

2. Turn interlock supply on.

3. Turn on 115 V or 230 Vac power.

15

Bird 8630B Series Moduload RF Load Resistor

4. Apply RF power to the load.

Normal Shutdown

Do not disconnect the line power first. Even a momentary

application of RF power to the load while the cooling circulation is

off will cause almost immediate destruction of the resistor element.

1. Turn RF power to the load off.

2. Wait five minutes, allowing pump and blower to return coolant to
ambient room temperature.

3. Turn ac power off.

 Note: Stopping the pump automatically opens the interlock

connection.

CAUTION

Emergency

Shutdown

Performance

Notes

With the use of interlock capability, the Load will automatically turn
off the transmitter’s RF power of an emergency arises.

If an emergency arises that is not a fault of the unit, always turn off
the source of RF power first, and then the ac power to the Load.

The electrical performance of the Series 8630 and 8630B RF loads is
affected by impurities or other chemical additives in the cooling
liquid. Therefore, the cooling liquid should be the coolant supplied
with the unit, or distilled water. Do not use any additives.

Thermal performance is affected by impurities, particularly those
which accumulate in the form of scale on the surface of the ceramic
tube and any other water passages. This results in an increase of
thermal resistance of the load, and in turn, may cause the load to
overheat and fail.

16

Chapter 5 Maintenance

This chapter covers cleaning, inspection, trouble-shooting, and
specifications for the 8630 and 8630B Series Moduload RF Load
Resistors.

Troubleshooting

The table below provides troubleshooting information for problems
which may occur during normal operation. Locate the problem,
review the possible causes, and perform the action listed. This
manual cannot list all malfunctions that may occur, or their
corrective actions. If a problem is not listed or is not corrected by the
listed actions, notify a qualified service center.

PROBLEM POSSIBLE CAUSE CORRECTION

Maintenance

Transmitter won’t
come on or shuts off
repeatedly

Excessive reflected
power

Coolant Leaking Loose connections

New or unusual
noises

Insufficient coolant flow Check coolant gauge

Defective flow switch Check flow switch
Defective pump Check pump
Overheating Check for sufficient coolant
Defective thermoswitch Check thermoswitch

Damaged resistor Check resistance value of RF section
Contaminated coolant Drain, flush and refill coolant system
Insufficient coolant Check for coolant leaks and add more

Worn or cracked tubing Replace defective tubing

Fans Check for loose fan blades

Pump

Check for blockage in circulatory system
Check for coolant leaks

Check for excessive room temperature
Check fans for jamming and grilles for

blockage

coolant

Check and tighten all connections

Check pump for signs of initial failure

Circulatory system Check for any sign of coolant leakage

17

Bird 8630B Series Moduload RF Load Resistor

Cleaning

The most important cleaning task is to remove accumulations of dust,
lint, and grime that could interfere with proper air circulation and
therefore efficient heat transfer. The heat exchanger surfaces,
particularly on the inside, should be checked periodically for possible
collection of dust and lint. When cleaning is necessary, follow these
instructions.

1. Remove and retain the 18 screws from the edges of the top panel,
and the top panel.

2. Clean off dust and lint, if any, with a radiator brush or stiff bristle
brush. A vacuum can be used to clean the coils if necessary.

3. Check under the ribs of the exhaust grille (at the side) for dust
collection. If there is a buildup, remove the grille and clean under
the ribs.

4. Replace top panel and screws.

Heavy coatings of lint on any surfaces of the heat exchanger unit can
impair the efficiency of the Moduload unit. Keep the surfaces of the
heat exchanger clean.

Radiator Surface The radiator surface, particularly on the inside, should be checked

periodically for possible collection of dust and lint. A heavy lint
coating on the inside surface of the radiator can impair the cooling
efficiency of the unit. Follow the instructions below for cleaning.

1. Remove the 18 screws from the edges of the top panel and remove
the panel.

2. Clean off any collected dust and lint with a radiator brush or any
stiff bristle brush.

3. Replace the top panel.

Connector and

Outside

The outside surface of the unit should also be wiped free of dust and
dirt at regular intervals. Use a soft, clean cloth dampened with mild
detergent. Check the condition of the RF coaxial connector. If needed,
clean the RF input connector using a selfdrying contact cleaner that
leaves no residue on the inaccessible portions.

18

General Maintenance

Maintenance

Measure Load DC

Resistance

Preparation:

y Tools: Common hand tools
y Ohmmeter with an accuracy of ± 1% at 50 ohms.
y Temperature of the load between 20°C to 25°C (68°F to 77°F)

Accurate measurement of the DC resistance between the inner and
outer conductors of the RF input connector will provide a good check
of the condition of the load resistor. Checking the DC resistance is
simply used to measure a change in the condition of the resistor over
time. The tracking of the DC resistance must start before the resistor
is first put into service. Perform the following steps and record the
value for future comparison. Check and record the resistance of the
load periodically according to use.

WARNING

Never attempt to connect or disconnect an RF cable while power is

on at the RF power source. Radiated RF energy is a potential health

hazard.

1. Turn off RF power and interlock circuitry before any electrical
disconnection.s are made.

Figure 7

Meter Lead

Placement

2. Disconnect RF coaxial line.

3. Connect the multimeter test leads across the center and outer
conductor of the load resistor. Refer to Figure 7.

4. Record the value of the resistance before the load is put into
service. Compare subsequent values with the latest reading. If the
values vary more than 2 ohms this could be an indication of a
failing resistive element.

 Note: It is recommended that this resistance check be performed

each time the load is to be used.

19

Bird 8630B Series Moduload RF Load Resistor

Water Flow Switch

Routine Service

Checks

The water flow switch should be inspected periodically for
accumulated scale and cleaned, if necessary, to permit free movement
of the sliding valve. This needs to be done after three to six months of
operation, depending on the amount of use. This should be done by
removing only the wired sensor plug using the following steps:

1. Drain the unit of its coolant.

2. Unscrew, counterclockwise, the 1-1/2 inch collar that holds the
sensor plug in the flow switch body.

3. Carefully pull the sensor plug out of the body, do not lose the
spring and sliding valve on the sensor plug stem.

4. Reverse the above steps to assemble.

The component is nonrepairable and must be replaced if its
performance is faulty. Operation can be checked by monitoring the
interlock circuits while starting or stopping the pump/motor with the
RF power off.

When the equipment is in use inspect the coolant level at regular
intervals. Normally check once or twice a week, more often if it is
used continuously or under high ambient temperatures. The coolant
level should remain at the upper gauge mark on the back panel,
whether the unit is running or not. For test measurement and
addition of liquid if required, Refer to the Coolant paragraph in
chapter 3. Use only distilled water and industrially pure ethylene
glycol. Do not use automotive antifreeze or deionized water.

20

Flushing the

System

Whenever maintenance work has been performed, including resistor
repair, or there is a reason to suspect that contamination has been
introduced or dislodged into the coolant, the system should be
thoroughly flushed. Do this by:

1. Run the load with coolant but without RF power applied for a
period of three to five minutes.

2. Drain the circulating system as completely as possible.

3. Fill the unit with fresh, clean, distilled water.

4. Repeat the sequence as required until the drained liquid is clear.

5. Fill the unit with distilled water and/or approved ethylene glycol
mixture per the Coolant paragraph.

Repair

Maintenance

The series 8630 and 8631B, 8635 and 8635B, 8638 and 8638B loads
are designed for independent, long term, trouble-free operation.
Regular mechanical maintenance procedures, other than routine
checks and cleaning care described previously, are not required. In
the case of malfunction of the unit or replacement of a major
component, resistor repair excepted, the entire load may be returned
to the factory. This applies especially to any unit still under the one
year warranty. Consult the factory.

 Note: Do not tamper with operational settings or perform other

unauthorized maintenance work during the first year. It could be cause
to void the warranty.

Field repair of the load resistor may be performed as described in the
Internal Repair of the Load Resistor paragraph. Other replacement
instructions that might be needed are given in this section.

RF Load Resistor

Unit Removal

If in performing the DC resistance check a significant change in
resistance is noted, or if for any reason the resistive element should
fail, the element should be replaced. Inexpensive replacement
resistors are available. Installation is described below.

Resistor repair in the load may be done without removing the water
connections; follow procedures in the Internal Repair of the Load
Resistor paragraph. They contain full dismounting and resistor
change procedures. The full load assembly may be removed from the
case as in the following procedure. Then follow the Internal Repair of
the Load Resistor section.

 Note: Notice the angular position of all elbows and associated

parts as they must be returned to relatively the same position
when reassembled.

WARNING

Never attempt to connect or disconnect an RF cable while power is on at

the RF power source. Radiated RF energy is a potential health hazard.

1. Turn off RF power and interlock circuitry before any electrical
disconnections are made.

2. Disconnect the RF coaxial line.
Models 8631 / 8631B and 8635 / 8635B — flanged, loosen and
remove the 3/8-16 bolt and nut sets that secure the flanges. Refer
to Figure 4.

21

Bird 8630B Series Moduload RF Load Resistor

Model 8638 and 8638B — unflanged, loosen one clamping band on
the load side of the connector sleeve. Refer to Figure 5.

3. Separate the transmission coaxial air line from the load connector.
Make sure the center conductor bullet remains in the transmission
line.

To remove the load resistor unit take off the top panel by removing
the 18 screws around its perimeter. Lift off the top panel assembly by
the handles. Continue following these instructions:

1. Remove, and retain the drain plug located near the bottom of the
rear panel of the unit and allow the coolant to drain.

 Note: Do not replace the drain plug with any substitute plug, use

the plug removed.

2. Unscrew the hose clamps on the hoses leading to the input elbow of
the flow switch and the output elbow on the water chamber. Use
an ordinary screwdriver.

3. Remove the hoses.

4. On the 8630, loosen the hex collar on the flow switch assembly and
remove the collar and sensor from the flow switch body. On the
8630B, disconnect the flow switch wires at their in-line connectors.
The output elbow on the side of the water chamber can now be
removed by unscrewing counterclockwise.

5. Remove the six 1/4-20 x 5/8 hex head bolts (on the inside of the
front panel) securing the load to the front panel.

 Note: When the six bolts securing the load to the front panel are

removed the outer conductor assembly will be disconnected. Hold this
assembly to keep it from falling and being damaged.

6. Temporarily reattach the outer conductor to the load body. Use
two or three of the 1/4-20 bolts (finger tight) for this purpose.

7. Tip up the the unit at the back enough to unscrew the flow switch
counterclockwise. The input elbow on the water chamber can be
taken off after the load is removed through the front panel.

8. If the load resistor is to be returned to the factory for repair, store
components with the Moduload unit until further use. Consult the
factory. If the unit is to be field repaired, proceed with resistor
replacement instructions as described in the Internal Repair of the
Load Resistor section.

22

9. Replace the load resistor by reversal of the above procedure. Be
sure to replace the coolant, per the coolant section. Check for leaks,
especially at the restored connections.

Maintenance

Pump/Motor

Removal

For removal of the pump motor, it should not be necessary to remove
the load resistor. Drain the unit of coolant by unscrewing the drain
plug on the lower rear panel, then remove the fan panel and rear
panel as follows:

1. On the 8630, release the fan panel by removing the 18 pan head
screws surrounding it. When free, it should not be necessary to
detach the terminal block connections to the fan; lay the panel to
the side.

On the 8630B, disconnect the two flow switch connectors, the two
quick-connects from the thermoswitch, the orange wire from the
front panel terminal block, and the red wire from the time delay
relay. Then disconnect the fan power cable connector. Be sure to
note the location of each wire for reassembly. The fan panel may
now be removed by removing the 18 pan head screws that attach
it to the unit.

2. Detach the back panel by, using a crescent or 7/8" hex socket
wrench, removing the two large hexagonal bolts that fasten the
coolant level gauge to the back panel.

3. Pull the coolant gauge off the panel.

4. Remove the 16, 8/32 screws, to free the panel.

5. Make note of, or mark, all wire connections before detaching.

6. Detach the 3-wire cable from the 3-lug terminal block on the inside
of the front panel. For reference, the color codes of the motor
supply wires generally match the twistlock (8630) or the power
(8630B) input wires, with the green going to the blue (8630) or the
green/yellow (8630B) ground wire from the socket (8630) or the
power entry module (8630B). Refer to Figure 8.

7. Release the hose clamp nearest the pump on the input hose and
carefully loosen the hose from the 90° input elbow at the center of
the helical pump head. In the same manner, loosen the output
hose from the straight-up fitting on the pumps helical outlet.

8. Reach under the input elbow with a screwdriver and loosen the
clamp band on the drain tube at the base of the volute. Free the
tube completely from the fitting

9. Use a 9/16" hex socket extension wrench or a small flat-end
wrench, to remove the two 3/8-16 nuts from the base studs holding
the motor feet. Lift the motor slightly to clear the studs, then
carefully inch the pump assembly forward while detaching the
hoses. The freed assembly may be lifted from the equipment out
the open side. Remove the wires, if needed, but make note of the
connections for assembly.

23

Bird 8630B Series Moduload RF Load Resistor

10. Note the positions of the fittings. Observe the slight downward tilt
of the 90° input elbow. Twist off, counterclockwise, the whole input
and output fittings parts. Remove the small drain elbow also. Store
the detached parts with the disassembled unit and return the
pump/motor unit to the factory for replacement.

11. Replace the pump/motor and assemble the unit by reversing the
disassembly procedure above. Refill the unit with coolant per the
instructions in the Coolant section.

Do not remove any fittings from the water chamber. The elbows

could be damaged, and may be difficult to restore them to their

original positions while keeping a water-tight seal. Check the

switch for free operation. Flush and clean with mild detergent of

CAUTION

necessary, and rinse thoroughly in clear water.

24

Figure 8

Wiring Diagram

GREEN

BLACK

WHITE

YELLOW

CAUTION

BLACK

INTERLOCK

230VAC 8AMP

60Hz 3AB

Maintenance

AC ON

YELLOW

BLACK

YELLOW

YELLOW

WHITE

WHITE

BLACK

BLACK

BLACK

WHITE

GREEN / YELLOW

WHITE

BLACK

GREEN / YELLOW

GREEN / YELLOW

25

Bird 8630B Series Moduload RF Load Resistor

Water Flow Switch

To replace the safety control water flow switch, begin with the same
process as described in the RF Resistor Load Disassembly section.
Remove the flow switch carefully or damage to the connections and
fittings may result.

1. With the top cover removed, and the unit drained of coolant,
loosen the clamp bands on the hose connections going to the load
water chamber output and the flow switch input. Remove the
hoses and move them out of the way.

2. Series 8630 only. Remove the 18, 8-32 x 1/4" Phillips head screws
in the perimeter of the pan panel assembly. Pull this panel out
sufficiently towards the rear of the unit to gain access. Usually
connection wires will not have to be disconnected.

3. Disconnect the wires that lead to the flow switch. On the 8630
series, one wire is connected to the thermoswitch located under the
coolant reservoir tank. The other wire is disconnected at a
connector in the wire harness.

4. On the 8630 series, unscrew the input elbow to the flow switch,
counterclockwise. The flow switch can be easily unscrewed
counterclockwise, depending on the orientation of the output elbow
on the load.s water chamber. This elbow may have to be turned or
possibly removed to allow the flow switch to swing freely when
being unsrewed

On the 8630B series, unscrew the input elbow to the flow switch

(counterclockwise).

 Note: If the fan interferes when removing the elbow, loosen the set

screw on the water chamber then rotate the water chamber until
the elbow is free from interference.

5. The flow switch is now free for repair or replacement.

6. Replace the flow switch and assemble the unit by reversing the
disassembly directions given above. When replacing the flow
switch on threaded fittings, coat only the external threads
sparingly with an acceptable pipe sealant compound. Coating only
the external threads reduces the chances of contaminating the
coolant.

Time Delay Relay The time delay relay is non-adjustable and is set for a 2 second delay.

The relay contacts can be used to interrupt the transmiter circuit in
the event of inadequate coolant flow or over temperature. The relay is
located on the upper left inside of the front panel.

The relay is not serviceable. To remove the realy perform the
following steps.

26

8630 Series

1. Loosen the 8-32 pan head screw at the top of the relay clamp, to
release the retaining prongs of the clamp.

2. Pull the delay relay cartridge straight out of the socket.

3. To install the new cartridge, put the center nib into the hole
provided. Rotate until the key way is engaged, and push in.

8630B Series

1. Remove the wires from the relay contacts. Note the color and
location of each wire for use in reassembly.

2. Remove the screw, nut, and washers that secure the relay to the
panel then remove the relay.

Replace Fuse Preparation:

Maintenance

y Observe general safety precautions.
y Tools needed: Common hand tools
y Disconnect ac power main.

1. Remove the fuse drawer from the ac receptacle.

2. Lift up on the tab that secures the drawer with the flat blade of a
screwdriver.

3. Pull the drawer straight out.

4. Replace with the same type and rating fuse. i.e., 15 Amp for the
115V unit and 8 Amp for the 230V unit.

Series 115V 230V
8630 15 amp 10 amp
8630B 15 amp 8 amp

5. Return the drawer to the receptacle.

6. Reconnect the ac power main and check the unit for proper
operation.

27

Bird 8630B Series Moduload RF Load Resistor

Load Resistor Internal Repair

The entire load resistor unit need not be removed from the Moduload
unit as a piece. It is simpler to disassemble it in place by the following
procedure. While following these instructions refer to Figure 9.

1. Drain coolant from the equipment by unscrewing the drain plug
from the lower back face of the equipment.

2. Remove the top panel of the unit. Unscrew the 18, 8-32 x 1/4"
phillips head screws and remove the coolant filler plug. Lift the lid
off by its handles.

3. Use a 5/64" hex wrench to remove the 8-32 x 1/8" socket set screw
on the circumference of the water chamber assembly near the load
housing seam.

4. Use a 7/16" end-wrench to unscrew the six 1/4-20 x 5/8" flange
mounting screws from the inside of the front panel. Take the
screws out to release the exterior flanges.

5. Use a leather strap type pipe wrench, or by twisting the housing
flange on the outside of the front panel, turn the housing
counterclockwise while firmly holding the water chamber and flow
switch at the back. A little extra torque will break the initial screw
compression, and the housing should screw off easily. Unscrew the
housing until the threads are disengaged and pull it out of the
front panel.

6. Temporarily reattach the outer conductor assembly to the load
housing to prevent displacement of the center conductor assembly.
Use two 1/4 -20 mounting screws placed through diametrically
opposite flange holes, fastened finger tight.

7. The Load Resistor is ready to be repaired.

Resistor Removal The removal of the resistor is to be done with the unit in a vertical

position, connector end down.

1. The water chamber complex, of the load resistor assembly, and
flow switch, with the attached adapters, may be dismounted, but
it is not required or recommended. Do this only by unscrewing the
wired sensor plug of the flow switch, with a 1-1/2 end-wrench. Do
not disconnect the wiring. Follow the instructions provided earlier
in this chapter for the entire load removal.

28

2. The O-Ring inlet seal in the water chamber may be removed and
replaced if necessary.

3. Remove the retainer sleeve and O-Ring sleeve backup. The inner
flow tube may be removed.

Maintenance

4. Grasp the resistor ground cap and remove it by pulling with a
slight rocking motion. This will expose the end of the resistor.

5. The resistor should still be nested inside the resistor fitting. If the
spacer ring is displaced, it will have to be repositioned.

6. Ensure the spacer ring is bottomed.

Inspection

Inspect the resistor and visible internal parts for damage. In most
cases, even in the event of a resistor failure, the resistor substrate will
remain intact. If so, continue the procedure in this section. Use the
special procedure for the replacement of fractured resistors or damaged
internal parts, as the condition of the resistor or internal parts require.

29

Bird 8630B Series Moduload RF Load Resistor

Econoload - Cut away view

12

13

7

Figure 9

2

8

3

Resistor

Replacement

4

10

1

6

14

11

5

9

1. Housing / Ass’y

2. Chamber, Water / Ass.y

3. Conductor, Outer / Ass.y

4. Conductor, Center / Ass.y

5. Cap, Resistor / Ass.y

6. Tube, Flow, Inner

7. O-Ring

8. Contact, Sleeve

9. O-Ring

10. Cap Screw St. Stl.

11. Set Screw St. Park

12. Label, Water Chamber

13. Insulator, Sleeve

14. O-Ring

Take particular care of the outside surface of the resistor. Treat this
surface gently, wiping with a soft cloth. Do not abuse it by firing,
sanding, or using any abrasive action.

30

1. Insert the new resistor into the load housing until it reaches the
resistor fitting.

2. Carefully rotate and rock the resistor until it starts to enter its
way into the resistor fitting. Push the resistor into the fitting until
it bottoms on the spacer ring. Ensure the spacer ring is in the

Maintenance

proper place. If the resistor seems to be loose, refer to the
procedure for the replacement of fractured resistors or damaged
internal parts below for instructions on how to tighten the resistor
fitting.

3. If damaged, replace the inner flow tube. If undamaged, place the
original flow tube inside the resistor and lower it until it reaches
the resistor fitting. Gently work and twist the inner flow tube until
it seats in the bottom of the resistor fitting.

4. Place the resistor ground cap on the exposed end of the resistor,
and press it into place. Slide the O-Ring down the inner flow tube
until it rests on the end of the resistor.

5. Slide the retainer sleeve down the inner flow tube until it rests on
the O-Ring, ensuring that the end of the retainer sleeve with the
larger inside diameter goes on first.

6. Check the O-Ring inlet seal to see that it is properly seated in its
groove in the inside of the water chamber subassembly.

 Note: Normally, the water chamber will not have been dismounted. Be

sure the screws are removed from the flange connecting the outer
conductor assembly.

7. Place the resistor housing through the front panel opening, and
into the water chamber. Gently turn the housing clockwise to
thread it on, eventually bottoming it in its original position.

8. Reverse the procedure of the RF Load Dismounting paragraph, to
restore the original condition. Do not replace the top panel until
after this section is completed.

9. Check the DC resistance between the outer and inner conductors;
it should be approximately 50 ohms. Refer to the Measure DC
Resistance section, and Figure 7.

10. If the resistance check passes, fill the unit with coolant,
performing the flush out procedures of the RF Load Dismounting
section, and check for leaks.

 Note: After the completion of this or any of the resistor repair

procedures, perform a 10 kW test on the ac line power. Perform this test
with the Moduload unit in operation for at least one-half hour, and check
the DC resistance before RF load use.

Replacement of Fractured Resistor or Damaged Internal Parts

Resistor Removal The load should already be disassembled to the point of the Resistor

Removal section, step 5.

31

Bird 8630B Series Moduload RF Load Resistor

1. Turn the load on end, with the RF input connector up, to allow
debris, if present, to fall out of the load housing.

2. Loosen and remove the 1/4-20 x 5/8 inch hex head screws from the
flanged end of the load housing assembly as shown in Figure 9.

3. Remove the outer conductor assembly.

4. Remove the input center conductor assembly by pulling it out of
the load housing assembly.

Input Center

Conductor

Assembly

Refer to Figure 10 while following the instructions below.

Model 8730A, (used in the Model 8635 and 8635B), 1-5/8 inch EIA
flanged input connector only.

1. Remove the 1/4-20 x 3/4 inch pan head machine screw and 1/4
inch split lockwasher by unscrewing the screw while holding the
center conductor stationary.

2. Remove the center conductor, the center conductor adapter, and
the insulator from the rest of the assembly.

3. Remove the resistor fitting by pushing the exposed end of the
fitting into the outer flow tube. The resistor fitting and any broken
pieces of resistor will fall from the opposite end of the outer flow
tube.

4. Inspect all O-Ring seals, metal and internal parts for damage. The
metal parts may be discolored or oxidized and may be cleaned by
rubbing them with fine abrasive cloth or silver cleaner. The Teflon
parts can be cleaned with detergent and water. If any of the
internal parts are damaged, they must be replaced to ensure
proper electrical and/or thermal performance of the load.

5. Insert the replacement resistor into the resistor fitting. If the
fitting is loose press the slotted finger contacts of the fitting
together slightly and try the resistor again. Continue this
procedure until a snug fit is obtained.

32

6. Reassemble the center conductor assembly by first replacing the
outer flow tube seal O-Ring. If needed, insert the resistor and
resistor fitting in position in the outer flow tube.

7. Replace Insulator center conductor adapter, and center conductor.
Tighten in place with 1/4-20 x 3/4 Inch pan head machine screw
and 1/4 inch split lockwasher.

Maintenance

Model 8731-101 Load (used in Model 8631 and 8631B), 3-1/8 inch EIA
flanged and Model 8738-101 Load (used in Model 8638 and 8638B), 3­1/8 inch unflanged input connector.

1. Loosen and remove the 3/8-16 hex nut, and the 3/8" split
lockwasher with a 9/16 socket or nut driver while holding the
center conductor stationary.

2. Remove the center conductor and the insulator, for Models 8731
and 8738.

3. Remove the resistor fitting by pushing the exposed threaded end of
the fitting into the outer flow tube. The resistor fitting and any
broken pieces of resistor will fall from the opposite end of the outer
flow tube.

4. Inspect all internal parts and O-Ring seals for damage. The metal
parts may be discolored or oxidized and may be cleaned by rubbing
them with fine abrasive cloth or silvercleaner. The Teflon parts
can be cleaned with detergent and water. If any of the internal
parts are damaged, they must be replaced to ensure proper
electrical and/or thermal performance of the load.

5. Insert the replacement resistor into the resistor fitting. If the
fitting is loose press the slotted finger contacts together slightly
and try the resistor again. Continue this procedure until a snug fit
is obtained.

6. Reassemble the input center conductor assembly by first replacing
the outer flow tube seal O-Ring, if necessary.

7. Insert the resistor fitting in position in the outer flow tube.

8. Replace insulator and center conductor for Models 8731 and 8738.
Tighten in place with the 3/8-16 hex nut and 3/8" split lockwasher.

Final Assembly 1. Replace the input center conductor assembly by lowering it into

the flanged end of the load housing assembly, and pressing it into
place.

2. Remount the outer conductor assembly, for Models 8730, 8731 or
8738, by placing the flange with the threaded holes against the
flange of the housing assembly. Tighten the six 1/4-20 x 5/8" hex
head cap screws securely.

3. Continue with the Resistor Replacement Instructions, given
earlier in this chapter.

Any maintenance or service procedure beyond the scope of those
provided in this section should be referred to a qualified service
center.

33

Bird 8630B Series Moduload RF Load Resistor

Figure 10

Center Confuctor Assemblies

Lockwasher

3

2

1

8738A Center

Conductor Assembly

45

2

1

8730A Center

Conductor Assembly

Lockwasher

3

4

5

34

Maintenance

Figure 11

Schematic Diagram, 8630, 10 kW Moduload, 115 V 50/60 Hz Supply

PUMP

WHITE

CAPACITOR

BROWN

YELLOW

FAN

GREEN

GREEN

RED

BROWNBROWN

BLACK

WHITE

GREEN

AC PLUG

WHITE

BLUE

ABOVE 6 GPM

NORMALLY CLOSED

FLOW SWITCH

WHITE

BLACK

o

BELOW 77 C

NORMALLY CLOSED

THERMOSWITCH

RED

BROWN

NORMALLY OPEN

1/2 - 3/4 SEC.

TIME DELAY

YELLOW

YELLOW

INTERLOCK

TRANSMITTER

BLACK

BLUE

115 VAC

35

Bird 8630B Series Moduload RF Load Resistor

CAPACITOR

GREEN

YELLOW

FAN

RED

Figure 12

Schematic Diagram, 8630, 10 kW Moduload, 230 V, 50/60 Hz Supply

PUMP

WHITE

GREEN

BROWNBROWN

BLACK

WHITE

GREEN

AC PLUG

WHITE

BLUE

ABOVE 6 GPM

NORMALLY CLOSED

FLOW SWITCH

WHITE

BLACK

o

BELOW 77 C

NORMALLY CLOSED

THERMOSWITCH

RED

BROWN

NORMALLY OPEN

1/2 - 3/4 SEC.

TIME DELAY

YELLOW

YELLOW

INTERLOCK

TRANSMITTER

BLACK

BLUE

230 VAC

36

Maintenance

Figure 13

Schematic Diagram, 8630B, 10 kW Moduload, 115 V and 230 V, 50/60 Hz Supply

FAN

WHITEWHITE

BLACKBLACK

GREEN / YELLOW GREEN / YELLOW

ORANGE

ABOVE 6 GPM

NORMALLY CLOSED

FLOW SWITCH

PUMP

BLACK

WHITE

GREEN

AC PLUG

BLACK

RED

YELLOW

WHITE

o

THERMOSWITCH

BELOW 77 C

NORMALLY CLOSED

BLACK

TIME DELAY

NORMALLY OPEN

2 SEC.

YELLOW

INTERLOCK

TRANSMITTER

BLACK

GREEN / YELLOW

INPUT VOLTAGE LINE FILTER

37

Bird 8630B Series Moduload RF Load Resistor

38

Storage and Shipment

Storage

Before storing the unit, follow the storage instructions in the

Storage section of the Maintenance chapter. Failure to follow the

If the unit is to be stored it should be stored filled with coolant if
possible. If storing the unit filled is not possible, drain the unit
following the drainage instructions below.

Drainage If the unit is to be stored partly drained or fully drained for two

weeks or longer, follow the drainage instructions below.

1. Flush the system as described in the manual five times if the
coolant has had any ethylene glycol added. Otherwise, flush the
system a minimum of one time per the manual.

Maintenance

CAUTION

instructions may result in damage to the unit.

Shipment

2. With the unit in a level position, remove the drain plug and allow
the fluid to drain from the system.

3. Tip the unit approximately 10 degrees from vertical, once each
side, to move more fluid out the drain opening.

4. Attach a fitting to the top of the expansion tank and plumb clean,
dry, filtered air regulated to 20 psi.

5. Allow air to purge the Moduload until relative humidity of output
is <20%.

6. Plumb a source of clean, dry nitrogen gas to the expansion tank
fitting with a regulator set to 5-9 psi.

7. Allow nitrogen to purge the Moduload until relative humidity of
output is <15%.

8. Disconnect nitrogen supply and fittings from the Moduload.
Reinstall drain plug and expansion tank cap.

CAUTION

Before shipping the unit, follow the shipping instructions in the

Maintenance chapter. Failure to properly prepare the unit for

shipping may result in damage to the unit.

If the unit is to be shipped, prepare the unit for shipping using the
drainage procedure below.

39

Bird 8630B Series Moduload RF Load Resistor

1. Flush the system as described in the manual five times if the
coolant has had any ethylene glycol added. Otherwise, flush the
system a minimum of one time per the manual.

2. With the unit in a level position, remove the drain plug and allow
the fluid to drain from the system.

3. Tip the unit approximately 10 degrees from vertical, once each
side, to move more fluid out the drain opening.

4. Attach a fitting to the top of the expansion tank and plumb clean,
dry, filtered air regulated to 20 psi.

5. Allow air to purge the Moduload until relative humidity of output
is <20%.

6. Plumb a source of clean, dry nitrogen gas to the expansion tank
fitting with a regulator set to 5-9 psi.

7. Allow nitrogen to purge the Moduload until relative humidity of
output is <15%.

8. Disconnect nitrogen supply and fittings from the Moduload.

When shipping the Moduload, use the original shipping package if
possible. If the original package is not available, use a heavy duty
corrugated box with shockabsorbing material around all sides of the
unit to provide firm cushioning, and to prevent movement in the
container. The container should be properly sealed.

Customer Service

Any maintenance or service procedure beyond the scope of those in
this chapter should be referred to a qualified service center.

If you need to return the unit for any reason, contact the Bird Service
Center for a return authorization. All instruments returned must be
shipped prepaid and to the attention of Bird Service Center.

Bird Service Center

30303 Aurora Road
Cleveland (Solon), OH 44139-2794
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]

Reinstall drain plug and expansion tank cap.

40

For the location of the Sales Office nearest you, give us a call or visit
our Web site at: http://www.bird-electronic.com

Specifications

Maintenance

Frequency Range
Power Rating
Impedance, Nominal
VSWR
Modes

1 kHz to 1000 MHz
10 kW Maximum
50 ohms

1.1 to 1.0
CW, AM, FM, SSB, & TV

Connectors

Model 8631 and 8631B
Model 8635 and 8635B
Model 8638 and 8638B

1

3-1/8" EIA flanged

1

1-5/8" EIA flanged

1

3-1/8" Unflanged

AC Power

115 VAC @ 9 Amps, 50/60 Hz
230 VAC @ 4.5 Amps, 50/60 Hz

Interlock Contact Ratings, Solid State Relay

125 VAC 10 A, resistive
230 VAC 5 A, resistive
+28 VDC 5 A, resistive
125 VAC 1/4 hp
Max switching voltage 250 VAC

Interlock Contact Ratings, Mechanical Relay

10 amps resistive at 30 VDC, 120 / 240 VAC

Ambient Temperature

With 100% distilled water

as coolant

With 35% ethylene glycol

as coolant

Operating Position
Dimensions, Nominal

Weight, Nominal

Finish

+5°C to +45°C (+41°F to +95°F)

-20°C to +35°C (-4°F to +95°F)

Horizontal only
22-1/8" L x 15-13/16" W x 15-15/16" H (562 x

402 x 405 mm)
113 lb with distilled water (51.3 kg)

103 lb without water (46.7 kg)
Grey Powder Coat

1 Suffix - 115 added for 115 V, 60 Hz, 9 Amp, single phase

Suffix - 230 added for 230 V, 50 Hz, 4.5 Amp, single phase
Suffix - 115-5 added for 115 V, 50 Hz, 9 Amp, single phase
Suffix - 230-6 added for 230 V, 60 Hz, 4.5 Amp, single phase

41

Bird 8630B Series Moduload RF Load Resistor

Replacement Parts

Model 8630B
Series Moduload
RF Load

DESCRIPTION QTY PART NUMBER

RF Load Resistor 1

Model 8631 and 8631B
Model 8635 and 8635B
Model 8638 and 8638B

Power Switch (illuminated)

115V

230V
Power Switch (not illuminated) 1 5A2384
AC Power Receptacle 1 5-1844
Fuse Drawer

115V

123V
Fuse 2

115V Model 15amp, 3AB Time-Delay Type MDA 15

230V Model 8amp, 3AB Time-Delay

230V Model 8amp, 5 mm x 20 mm Time-Delay 8A
Power Cord 1

115 V

230 V
Fan Guard

Model 8630

Model 8630B
Fan Motor Assembly 1

Model 8630, 115V

Model 8630, 230V

Model 8630B, 115V

Model 8630B, 230V
Fan Starting Capacitor (model 8630 only) 1 5-873-2
Pump/Motor Unit 1

115 / 230VAC, 60 Hz.

115 / 230VAC, 50 Hz.
Flow Switch Assembly

Model 8630

Model 8630B
Time Delay Relay:

Model 8630, 115V

Model 8630, 230V

Model 8630B (115V and 230V)
Relay Socket (model 8630 only) 1 8640-561

1

1

6

1

1

8731-101
8730A051
8738-101

5-1842-1
5-1842-2

5-1845
5A2310

5-1828-36
5A2257-25
5A2257-25

5-1836
5-1837

5-1923
5A2789-2

8630-644-1
8630-644-2
5A2770-1
5A2770-2

5-1053-1
5-1053-2

8630-108
8630B108

5-1627
5-1625
5A2787-1

42

Maintenance

Over Temperature Thermoswitch

Model 8630

Model 8630B
Coolant Tank Assembly

Model 8630

Model 8630B

1

8630-013
5A2788-1

1

8630-102

8630-089
Filler Plug 1 8630-038
Silicone Rubber Hose, 5/8" diameter 1 **8630-065
Filler Plug Seal (O-Ring) 1 5-814
Carrying Handle (kit) 2 5-375
Silicone Rubber Hose, 3/4" diameter 1 **8640-064
Drain Plug 1 8640-036
Drain Plug Seal (O-Ring) 1 5-428
Hose Clamp, 5/8" 8 5-681
Hose Clamp, Diamond 3/4" 2 5-742
Breather Vent 1 5-1350
Drain Body Assembly 1 8630B-099
Coolant Gauge Body 1 5-1200
Pump Inlet Fitting Assembly 1 8650-081
Relay Retaining Clamp (model 8630 only) 1 8630-193
Load, Outlet - elbow 1 8630-175
Pump Outlet Tube Assembly 1 8630-176
Flow Switch Inlet Fitting (elbow) 1 8630-033
Flow Switch to Load Fitting (elbow) 1 8630-178
Interlock Terminal Strip

Model 8630
Model 8630B

1

5-768-2

5A1840-2
Interlock Terminal Strip Cover (model 8630B only) 1 5A1840-2-C
Line Filter (ac input) (model 8630B only) 1 5A2792-1

**Measure hose length when ordering.

For All -N Models

DESCRIPTION QTY PART NUMBER

Fan Panel Assembly:

115V
230V

Fan, Service Assembly:

115V
230V

Fan Propeller 1 5A2457

1

8630-172-3
8630-172-4

1

8630-644-3
8630-644-4

43

Bird 8630B Series Moduload RF Load Resistor

Model 8630 and
8630B Series
Loads

RF Load Assembly Parts for Moduload Models 8731-101, 8738-101, and
8730A051

DESCRIPTION QTY PART NUMBER

Resistor 1 8731-031
Resistor Ground Cap Rear Seal O-Ring 1 5-176
Water Chamber Subassembly 1 8731-025
Inlet Seal O-Ring 1 5-430
Retainer Sleeve 1 8731-023
Sleeve Backup O-Ring 1 5-1142
Inner Flow Tube 1 8731-022
Resistor Ground Cap 1 8731-007
Housing Assembly 1 8731-002
Resistor Ground Cap Internal Seal O-Ring 1 5-187
8-32 x 1/8" Cup Point Socket Set Screw 1 1128-0201-25
Outer Flow Tube 1 1128-0201-25
Outer Flow Tube Seal O-Ring 1 5-099
Insulator 1 8731-018

Front Connector Parts are Assigned Per Model Type Below:

Model 8635B Load — 8730A051 - 1-5/8" EIA Flanged Connector - 50 ohms

DESCRIPTION QTY PART NUMBER

Center Conductor Assembly 1 8730-003
Resistor Fitting 1 8730-008
Center Conductor Adapter 1 8730-009
Center Conductor 1 8730-010
Outer Conductor Assembly 1 8730-002
1/4-20 x 3/4" Button Head Machine Screw 1 1121-1217-00
1/4" Split Lockwasher 1 Standard

Model 8631B Load — 8731-101 - 3-1/8" EIA Flanged Connector - 50 ohms

DESCRIPTION QTY PART NUMBER

Center Conductor Assembly 1 8731-005
Resistor Fitting 1 8731-017
Center Conductor 1 8731-015
3/8-16" Hex Nut 1 Standard
3/8" Split Lockwasher 1 Standard
Outer Conductor Assembly 1 8731-004

44

Model 8638B Load — 8738-101 - 3-1/8" Unflanged Connector - 50 ohms

DESCRIPTION QTY PART NUMBER

Center Conductor Assembly 1 8738-003
Resistor Fitting 1 8731-017
Center Conductor 3/8-16" Hex Nut 1 Standard
3/8" Split Lockwasher 1 Standard
Center Conductor 1 8738-005
Outer Conductor Assembly 1 8738-002

For all Models

DESCRIPTION QTY PART NUMBER

Resistor Spacer Ring 1 8731-008
1/4-20 x 5/8" Hex Head Cap Screw 6 1121-1008-00

Optional Items

Maintenance

DESCRIPTION QTY PART NUMBER

Ethylene glycol 1 gal 5-1134-3
Repair and Replacement Kit, P/N

Consists of:

Coolant and Container Assy. (8630-197),
50 ohm resistor (8731-031-1), and
instruction sheet (921-8630-196).

1 8630-196

45

Limited Warranty

All products manufactured by Seller are warranted to be free from defects in
material and workmanship for a period of one (1) year, unless otherwise
specified, from date of shipment and to conform to applicable specifications,
drawings, blueprints and/or samples. Seller’s sole obligation under these
warranties shall be to issue credit, repair or replace any item or part thereof
which is proved to be other than as warranted; no allowance shall be made for
any labor charges of Buyer for replacement of parts, adjustment or repairs, or
any other work, unless such charges are authorized in advance by Seller.

If Seller’s products are claimed to be defective in material or workmanship or not
to conform to specifications, drawings, blueprints and/or samples, Seller shall,
upon prompt notice thereof, either examine the products where they are located
or issue shipping instructions for return to Seller (transportation-charges
prepaid by Buyer). In the event any of our products are proved to be other than
as warranted, transportation costs (cheapest way) to and from Seller’s plant, will
be borne by Seller and reimbursement or credit will be made for amounts so
expended by Buyer. Every such claim for breach of these warranties shall be
deemed to be waived by Buyer unless made in writing within ten (10) days from
the date of discovery of the defect.

The above warranties shall not extend to any products or parts thereof which
have been subjected to any misuse or neglect, damaged by accident, rendered
defective by reason of improper installation or by the performance of repairs or
alterations outside of our plant, and shall not apply to any goods or parts thereof
furnished by Buyer or acquired from others at Buyer’s request and/or to Buyer’s
specifications. Routine (regularly required) calibration is not covered under this
limited warranty. In addition, Seller’s warranties do not extend to the failure of
tubes, transistors, fuses and batteries, or to other equipment and parts
manufactured by others except to the extent of the original manufacturer’s
warranty to Seller.

The obligations under the foregoing warranties are limited to the precise terms
thereof. These warranties provide exclusive remedies, expressly in lieu of all
other remedies including claims for special or consequential damages. SELLER
NEITHER MAKES NOR ASSUMES ANY OTHER WARRANTY WHAT­SOEVER, WHETHER EXPRESS, STATUTORY, OR IMPLIED, INCLUDING
WARRANTIES OF MERCHANTABILITY AND FITNESS, AND NO PERSON
IS AUTHORIZED TO ASSUME FOR SELLER ANY OBLIGATION OR
LIABILITY NOT STRICTLY IN ACCORDANCE WITH THE FOREGOING.