INSTRUCTION BOOK
TERMALINE® LOAD RESISTOR
SERIES 8930
©Copyright 2008 by Bird Electronic Corporation
Instruction Book Part Number 920-8930S Rev. E
Termaline
®
is a Registered Trademark
of Bird Electronic Corporation
This page intentionally left 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 apply 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 person 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 8930 Series Termaline Coaxial 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 follwed.
The caution symbol appears on the equipment indicating
there is important information in the instruction manual
regarding that particular area. See page 15 for specific
cautions.
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
The vent plug must be used at all times when the unit is operating or
cooling. Failure to do so could result in an explosion or severe burns.
WARNING
Turn off ac power and RF power when attaching the power cable.
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.
ii
WARNING
Disconnect the unit from all power sources before servicing.
The unit may be energized from multiple sources.
The potential for electric shock exists.
WARNING
Do not operate with side panel removed. Doing so could result in
personal injury.
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
Do not block airflow. The air intake vent on the bottom of the load must
not be obstructed.
CAUTION
This load is designed for operation in a horizontal position only, with
the vent plug up. Do not use in any other manner.
CAUTION
If installed, connect optional interlock before applying RF power.
CAUTION
Check the local electrical code for proper ac hookup prior to operation of
the unit. Make sure the neutral or return hookup is only used for that
purpose.
CAUTION
Maximum power is 2,500 W when the blower is not running. If the
indicator light should turn off, immediately reduce RF power to less
than 2,500 W.
CAUTION
Use only Bird coolant, P/N 5-1070, to prevent damage to the load.
iii
Bird 8930 Series Termaline Coaxial Load Resistor
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 DESCARGÉAS ELCTRICAS, NO REALICE NINGÚN
SERVICIO A MENOS QUE ESTÉ CAPACITADO PARA HACERIO.
WARTUNG
ANWEISUNGEN FÜR DIE WARTUNG DES GERÄTES GELTEN NUR
FÜR GESCHULTES FACHPERSONAL.
iv
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.
CONNECT INTERLOCK TO TRANSMITTER/GENERATOR/
AMPLIFIER BEFORE OPERATING.
BRANCHER LE VERROUILLAGE À L’ÉMETTEUR/
GÉNÉRATEUR/AMPLIFICATEUR AVANT EMPLOI.
CONECTE EL INTERBLOQUEO AL TRANSMISOR/GENERADOR/
AMPLIFICADOR ANTES DE LA OPERACION.
VOR INBETRIEBNAHME VERRIEGELUNG AM SENDER/
GENERATOR/VERSTÄRKER ANSCHLIESSEN.
PRIMA DI METTERE IN FUNZIONE L’APPARECCHIO, COLLEGARE
IL DISPOSITIVO DI BLOCCO AL TRASMETTITORE/GENERATORE/
AMPLIFICATORE.
v
Bird 8930 Series Termaline Coaxial Load Resistor
This instruction book covers the models listed below:
Connector 115 Vac 230 Vac
Female LC 8931-115 8931-230
1-5/8" EIA Flanged 8932-115 8932-230
3-1/8" EIA Flanged 8936-115 8936-230
About This Manual
3-1/8" Unflanged, Flush
8937-115 8937-230
Center
3-1/8" Unflanged,
8938-115 8938-230
Recessed Center
This instruction book is arranged so that essential information on safety
is contained in the front of the book. Reading the Safety Precautions
Section before operating the equipment is strongly advised.
The remainder of this Instruction Book is divided into Chapters and
Sections. At the beginning of each chapter a general overview will be
given, describing the contents of that chapter.
Operation
First time operators should read Chapter 1 – Introduction, 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 section.
Maintenance
All personnel should be familiar with preventative maintenance found in
Chapter 5 – Maintenance. If a failure should occur, the troubleshooting
section will aid in isolating and repairing the failure. Parts lists and
repair instructions are also in this chapter.
Changes
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
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.
vi
Table of Contents
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
About This Manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . vi
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Items Supplied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Items Required but not Supplied. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Optional Accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Load Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Power Rating Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Thermal Interlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Unpacking and Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Thermoswitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Interlock Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
AC Power Connection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Connecting RF Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . 11
Blower Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Operation Under Abnormal Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Emergency Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
vii
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
DC Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Repair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
RF Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Load Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Indicator Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Storage and Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Customer Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Available QC Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
viii
Chapter 1 Introduction
Bird 8930 Series Loads are general purpose, 50 ohm, coaxial RF
transmission line terminations, useful as standby reject loads for
single or double sideband transmitters. They provide accurate,
dependable, and low reflection line terminations over a frequency
range of dc – 1000 MHz. Up to 10,000 watts can be dissipated.
The loads have a coolant chamber surrounded by radiator fins. The
front and rear fins form mounting flanges which can be used as
supports for freestanding use or as brackets for fixed mounting. A
vent plug at the top of the unit relieves internal pressure from coolant
expansion. A blower with three axial fans is on the bottom of the load.
The load’s simple and rugged design minimizes maintenance
requirements.
Items Supplied y Load Resistor: Pre-filled with coolant at the factory
y Detachable 3-wire power cable (without male plug for 230 Vac
power cable)
Items Required but
not Supplied
Optional
Accessories
y One Shipping Plug
y One Vent Plug
y Instruction Manual
y Coupling Kit: Connects the load to the RF line
y Male plug for the power cable (230 Vac only)
y Interlock Thermoswitch: Automatically shuts off the transmitter
to prevent overheating of the load
1
Bird 8930 Series Termaline Coaxial Load Resistor
MANUAL
AUTOMATIC
AC ON
9.5”
(241mm)
7”
(178mm)
(4) MTG.
HOLES
29”
(737mm)
33-3/8”
(847 mm)
14-7/8”
(378 mm)
FAN CONTROL
THERMOSWITCH
INTERLOCK
THERMOSWITCH
(OPTIONAL)
VENT PLUG
FAN GRILL
SIDE BAFFLE
SCREWS
“QC” CONNECTOR
SCREWS
CLAMPING BAND
AND O-RING
FUSE
DRAWER
Figure 1
Bird 8930 Series
Outline Drawing
2
Chapter 2 Theory of Operation
Load Resistor Bird 8930 Loads consist of a thin-film-on-ceramic resistor immersed
in a dielectric coolant. The resistor, individually selected for its
accuracy, is enclosed in a special housing. When surrounded by the
coolant, this produces a uniform, practically reflectionless line
termination over the specified frequencies.
Coolant The load is cooled by forced air and natural fluid convection currents.
The coolant, chosen for its desirable dielectric and thermal
characteristics, carries heat from the resistor to the walls of the
cooling tank, where radiator fins surrounding the tank transfer the
heat to the forced air flow.
When the coolant is heated, thermal expansion causes an increase in
the internal pressure. A vent plug relieves this pressure while
protecting the opening from dirt or other contaminants.
Fans Forced airflow is provided by three axial fans beneath the heat
exchanger. Baffles direct the air over the radiator fins for more
efficient cooling. A passive, normally open control thermoswitch
closes when the coolant reaches 60 °C (140 °F), turning the fans on.
Power Rating
Reduction
The baffles interfere with the free flow of normal air currents, causing
a 75% reduction in heat transfer efficiency if the forced airflow is
stopped. The maximum power dissipation when the fans are not
functioning is 2.5 kW.
Thermal Interlock When installed, a passive, normally closed overtemperature thermo-
switch opens above the maximum safe load temperature of 226 °C
(439 °F), turning off transmitter power. The interlock will not permit
use of the transmitter until the load has reached a safe temperature.
3
Bird 8930 Series Termaline Coaxial Load Resistor
O-ring seal
O-ring seal
Figure 2
Shipping Plug
Figure 3
Vent Plug
4
Chapter 3 Installation
This chapter provides information for on-site requirements,
unpacking, inspection, and preparing the load for use.
Unpacking and
Inspection
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.
CAUTION
Do not block airflow. The air intake vent on the bottom of the load
must not be obstructed.
Place the load in a dry, dust and vibration free environment. Do not
use outdoors or in areas of condensing humidity. Allow at least 15"
(40 cm) of clearance on all sides of the load, or mount it over a suitably
reinforced opening measuring 26"L x 7"W x 5"D (660 x 178 x 127 mm).
CAUTION
This load is designed for operation in a horizontal position only,
with the vent plug up. Do not use in any other manner.
Bird 8930 Loads are intended for stationary or fixed use. The
mounting brackets on front and rear faces have four mounting holes
arranged in a 7" x 27
with a
3
⁄
" (9.5 mm) diameter max.
8
23
⁄
" (114.3 x 526.3 mm) rectangle. Use a screw
32
5
Bird 8930 Series Termaline Coaxial Load Resistor
Setup
WARNING
The vent plug must be used at all times when the unit is
operating or cooling. Failure to do so could result in an
explosion or severe burns.
y Before first using the load, get a resistance baseline for future
maintenance. Refer to
“DC Resistance” on page 16 for instructions.
y Remove the shipping plug from the load and replace it with the
vent plug. Refer to
Thermoswitch Bird 8930 Loads can be equipped with an optional interlock
thermoswitch, P/N 8890-017. It is normally closed, opening at 226 °C
(439 °F), with a rating of 10A @ 120Vac and 5A @ 230Vac.
A control thermoswitch, P/N 8892-333, is used to control the blower
assembly. It is normally open, closing at 60 °C (140 °F), with a rating
of 10A @ 120Vac and 5A @ 230Vac.
The vent plug must be used at all times when the unit is
operating or cooling. Failure to do so could result in an
Figure 2 and Figure 3 to identify the plugs.
WARNING
explosion or severe burns.
To install or replace a thermoswitch, follow these instructions:
1. Replace the vent plug with the shipping plug.
2a. Interlock Thermoswitch: Supporting the load to prevent damage
to the RF connector, stand the unit on its front with the connector
down. In this position there is no danger of coolant spillage.
2b. Control Thermoswitch: Stand the unit on its back end, with the
connector up. In this position there is no danger of coolant spillage.
3. Remove the socket plug (or old thermoswitch), using a
9
⁄
"
16
hex wrench.
4. Insert the new thermoswitch. Sparingly apply pipe sealing
compound to the external threads, only, of the thermoswitch. Do
not contaminate the coolant with pipe sealant.
5. Check for coolant leaks upon completion.
6
Installation
Interlock
Connection
If installed, connect the optional interlock thermoswitch to the
interlock as follows (see
Figure 4):
CAUTION
If installed, connect optional interlock before applying RF power.
1. Unscrew the larger knurled ring-nut (A) at the lower end of the
coupling jack assembly. Pull it off the thermoswitch jack (B).
Unscrew the small knurled cover fitting (C) from the base plug (D)
of the connector to release the base.
2. Thread the interlock wires through the clamp (E) with the
washers (F) inside and with its threaded fitting in place. Service
the interlock wires with short tips and put spaghetti sleeves over
the wire ends if necessary.
3. Securely solder the interlock leads to the lugs (G) of the connector
base.
+ NOTE: The ring-nut (A) must be in place over the base plug (D)
with the knurled end facing out.
4. Screw on the cover fitting (C), then fasten the cable clamp (E) in
place and tighten both yoke screws (H).
Figure 4
Thermoswitch
Assembly
5. Put the plug back on the thermoswitch and tighten the nut (A).
7
Bird 8930 Series Termaline Coaxial Load Resistor
BOLT BULLET LOADRF COAXIAL LINE
AC Power
Connection
Check the local electrical code for proper ac hookup prior to
operation of the unit. Make sure the neutral or return hookup is
Turn off ac power and RF power when attaching the power cable.
The ac power supply required for this unit is 115/230 V, depending on
the model, @ 50/60 Hz, 1
“cold” (65
°C) ac inlet.
CAUTION
only used for that purpose.
WARNING
φ. The blower is equipped with an IEC 320
Connecting RF
Power
Figure 5
Swivel Flanged
Coupling
After installing the load, the RF transmission line can be attached
using standard coaxial line coupling kits.
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.
“QC” Connector Coupling: Use 50 ohm coaxial cable such as
RG-218/U or -220/U (-17A or -19A), appropriate for the frequency and
power level of operation. Use a cable connector which will mate with
the one on the load.
Swivel Flanged Coupling: To couple the swivel flange with a flanged
RF transmission line, use an appropriate coupling kit. Refer to
Figure 5 while following the instructions below:
y Insert the center bullet and push it in until it is fully seated.
y Connect the coaxial input in a straight line and push carefully on
the center conductor to close.
8
Figure 6
RF COAXIAL
LINE
CLAMPING
BANDS
CONNECTOR
SLEEVE
BULLET
LOAD
Unflanged
Coupling
Installation
+ NOTE: The swivel flange on the load makes connection
independent of the orientation of the fixed flange on the coaxial
input outer conductor.
y Insert the bolt sets and tighten evenly all around to transmission
line manufacturer’s recommended torque. Use all of the bolts.
Unflanged Coupling: To couple the unflanged connector with an
unflanged RF line, use an appropriate coupling kit. Refer to
while following the instructions below:
Figure 6
y Insert the center bullet and bottom it on the midpoint nibs.
y Position the outer sleeve, with clamping bands, over the input
connector.
y Set the transmission line snugly against the coupling stops.
y Position the clamping bands evenly about 3/4” from the ends of
the sleeve.
y Tighten the clamping bands.
9
Bird 8930 Series Termaline Coaxial Load Resistor
10
Chapter 4 Operating Instructions
CAUTION
Maximum power is 2,500 W when the blower is not running. If the
indicator light should turn off, immediately reduce RF power to less
than 2,500 W.
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.
Blower Controls Bird 8930 Loads are equipped with a control switch and indicator
light on the front of the blower, underneath the RF connector.
The switch is labelled “MANUAL/AUTOMATIC”. When the switch
is set to MANUAL, the fans will run continuously. When set to
AUTOMATIC, the fans will be turned on when the coolant reaches a
preset temperature. The indicator light, labeled “AC ON”, will turn on
whenever the unit is connected to ac power.
Normal Operation y Check that the indicator light is on.
y Set the switch to MANUAL momentarily to check that the fans
are working properly, then set the switch back to AUTOMATIC.
y Apply RF power.
Operation Under
Abnormal
Conditions
If the indicator light turns off or the fans stop unexpectedly,
immediately turn off RF power or reduce it to less than 2,500 W.
Refer to
“Troubleshooting” on page 13 to correct the problem. A
properly connected interlock will prevent overload.
The load can be subjected to higher power levels for short intervals. If
this is likely, make sure the interlock is properly connected to prevent
damage to the load.
11
Bird 8930 Series Termaline Coaxial Load Resistor
Shutdown y Turn off RF power at the source.
y Wait approximately 15 minutes, or for the fans to stop running.
This will allow the load to cool without causing heat stress.
y Turn off the blower.
Emergency
Shutdown
Turn off RF power at the source.
If the interlock thermoswitch is properly connected, RF power will be
automatically turned off when the coolant temperature reaches an
unsafe level.
12
Troubleshooting
Chapter 5 Maintenance
This chapter covers routine maintenance, troubleshooting,
specifications, and replacement parts for Bird 8930 Loads.
WARNING
Disconnect the unit from all power sources before servicing.
The unit may be energized from multiple sources.
The potential for electric shock exists.
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.
The table below contains troubleshooting information for problems
which can occur during normal operation. 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
No air flow from
blowers; “BLOWER
ON” light off
No air flow from
blowers; “BLOWER
ON” light on
Air flow from blowers;
“BLOWER ON” light off
Unplugged power cable Connect the power cable
No ac power Make sure ac power is properly connected
and turned on
Fuse burnout Replace fuse after correcting the burnout
cause (see “Fuse” on page 19)
Fan obstructed by bent grill Straighten the grill
Fan motors overheated Clean the grill and fan blades
(see “Cleaning” on page 15)
Fan motors burnt out Replace fan (see “Fans” on page 21)
Lamp burnout Replace lamp
(see “Indicator Light” on page 19)
13
Bird 8930 Series Termaline Coaxial Load Resistor
MANUAL
AUTOMATIC
AC ON
FAN GRILL
SIDE BAFFLE
SCREWS
“QC” CONNECTOR
SCREWS
CLAMPING BAND
AND O-RING
FUSE
DRAWER
PROBLEM POSSIBLE CAUSE CORRECTION
Leaking coolant Loose clamping band Tighten the clamping band
High or low dc
resistance
Defective or improperly
installed O-ring
Loose RF input connector Tighten connector
Faulty RF input connector Model 8931: Replace connector
Replace the O-ring
(see “Load Resistor” on page 18)
(see “RF Connector” on page 18)
All other models: Return the unit for service
Faulty resistor Replace the resistor
(see “Load Resistor” on page 18)
Overheating radiator RF power too high Lower RF power (see “Specifications” on
page 23 for maximum RF power)
Coolant level too low Check the coolant level. Add coolant if
necessary (see “Coolant” on page 17)
Coolant degraded Replace coolant (see “Coolant” on page 17)
Faulty control thermoswitch Replace control thermoswitch
(see “Thermoswitch” on page 6)
Faulty resistor Replace the load resistor
(see “Load Resistor” on page 18)
Figure 7 Maintenance and Repair Locations
14
Maintenance
Cleaning The outside surface of the unit should be wiped free of dust and dirt
Maintenance
+ NOTE: Figure 7 on page 14 shows the location of components
which may be referred to in this section.
when necessary. Excessive dust on the cooling fins will interfere with
heat dissipation. Clean the RF connector, both metallic and
insulating surfaces, with a dry, non-residue forming solvent.
WARNING
Disconnect the unit from all power sources before servicing.
The unit may be energized from multiple sources.
The potential for electric shock exists.
WARNING
Do not operate with side panel removed. Doing so could result in
personal injury.
Radiator: To clean the radiator fins, partial disassembly of the load
will be required. Follow the instructions below:
1. Unscrew the unpainted 10-32 x
1
⁄
" Phillips head screws on the
4
front and rear radiator faces, just below the RF connector.
2. Unscrew all four pairs of 10-32 x
5
⁄
" Phillips head screws on the
8
sides of the radiator, just above the fan grill.
3. Remove the side panels and clean the fins.
4. Replace the side panels and screw into place.
Fans: Follow these steps to clean the fans:
1. Pull the fan grill out so that its upper flanges come free from the
housing.
2. Pull the grill down and remove it.
3. Use a soft, damp cloth to remove dust from both sides of the fan
blades. Do not use a cleaning solution that will attack the plastic
parts of the fan.
4. Replace the fan grill.
Inspection Inspect the unit every six months. Check for coolant leakage around
the clamping band and the thermoswitch. Also check for corrosion.
15
Bird 8930 Series Termaline Coaxial Load Resistor
DC Resistance Measuring the dc resistance between the inner and outer conductors
of the RF connector shows changes in the load over time, a good check
of the load resistor’s condition. Under normal operating conditions,
the resistor should provide at least 5,000 hours of operation before
requiring any additional service. DC resistance tracking must start
before the load is put into service, and should be measured annually.
Perform the following steps and record the value for future
comparison. Make sure that you have an ohmmeter with an accuracy
of ±1% at 50 ohms and that the load temperature is between 20 and
25 °C (68 to 77 °F) before starting.
Figure 8
Measuring
Resistance
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.
y Turn off the RF power and interlock circuitry.
y Disconnect the RF line.
y Connect the multimeter test leads to the center and outer
conductor of the load resistor. Refer to
Figure 8.
y Compare the measured value with the previous measurement and
with the baseline resistance, measured when the load was put
into service. If the new value differs from either of these by more
than 2 ohms this could indicate a failing resistor.
16
Coolant Coolant lifetime will vary greatly depending on the operating
temperature. For heavy use (full RF power for long times, high
ambient temperature, 50 Hz ac supply), check the coolant every 500
hours. If the load has only had light duty (fraction of full power, low
ambient temperature, 60 Hz ac supply), then coolant inspection may
only be necessary every 2,000 hours.
+ NOTE: Correct any coolant leakage before inspection. (See
“Troubleshooting” on page 11)
WARNING
Disconnect the unit from all power sources before servicing.
The unit may be energized from multiple sources.
The potential for electric shock exists.
To inspect the coolant:
y Remove the load resistor (Refer to “Load Resistor” on page 18).
Maintenance
CAUTION
Use only Bird coolant, P/N 5-1070, to prevent damage to the load.
y The coolant should be clear, with a faint yellow tinge, and have a
slightly sweet smell. If it is black with a burnt or acrid smell,
drain it and add about 6.7 gal (25.4 L) of coolant.
y With the load still on end, the coolant level should be 4
inches (125 mm) below the top of the resistor assembly mounting
ring, at ambient temperature. Add coolant if necessary.
3
⁄
4
to 5
17
Bird 8930 Series Termaline Coaxial Load Resistor
Repair
+ NOTE: Figure 7 on page 14 shows the location of components
which may be referred to in this section.
WARNING
Disconnect the unit from all power sources before servicing.
The unit may be energized from multiple sources.
The potential for electric shock exists.
RF Connector The Model 8931, only, has a Bird “QC” connector which allows easy
changing of the RF connector. This does not disturb the coolant seal
or affect the electrical continuity of the load. To change the connector:
y Remove the four screws at the corners of the RF connector.
y Pull the connector straight out.
y Push the new connector in. Make sure that the center pin on the
connector is properly seated in the mating socket on the load.
y Replace the screws.
+ NOTE: If not using the LC connector normally supplied, frequency
and power must be limited to the capabilities of the connector.
Load Resistor To change the load resistor assembly:
1. Remove the vent plug and install the shipping plug.
2. Stand the unit on its back with the connector end up. In this
position there is no danger of the coolant pouring out through the
socket plug hole.
3. Unscrew and remove the clamping band.
4. Lift the load resistor assembly out of the tank and allow any
coolant to drip back into the tank.
5. Check the O-Ring. It should be free of twists and positioned
evenly around the flange of the resistor housing. If the O-ring
shows signs of deterioration (e.g. is no longer pliable or has
surface cracks) replace it.
6. Replace the entire load resistor assembly. It cannot be further
disassembled.
18
7. Put the clamping band in place and tighten it.
8. Remove the shipping plug and install the vent plug.
Indicator Light
Maintenance
WARNING
Disconnect the unit from all power sources before servicing.
The unit may be energized from multiple sources.
The potential for electric shock exists.
1. Remove the four 8-32 pan head screws from the front and back of
the base frame.
2. Pull the fan guard straight off the bottom.
3. Remove the quick disconnects on the light and unscrew the
retaining sleeve.
4. Remove the light unit.
5. Remove the lens while pressing both locking tabs.
6. Press the housing’s center slot with a small screwdriver to release
the lamp.
7. Push the new lamp into the housing until it snaps into place.
8. Replace the lens, then put the light unit back in place.
9. Replace the fan guard and screw it into place.
Fuse The fuse is located in the AC module on the back of the blower.
To replace the fuse:
WARNING
Disconnect the unit from all power sources before servicing.
The unit may be energized from multiple sources.
The potential for electric shock exists.
1. Correct the fuse burnout cause.
+ NOTE: Common causes include stuck or blocked fans or a short
circuit in the motor or blower wiring.
2. Press the locking tab on the fuse drawer and remove the drawer.
3. Replace the fuse. See “Specifications” on page 23 for fuse type and
current rating.
4. Press the drawer into the AC module until it locks into place.
5. If the fans still do not run or if the fuse burns out again, return
the unit to Bird for service.
19
Bird 8930 Series Termaline Coaxial Load Resistor
INDICATOR
LIGHT
FAN
A
FAN
B
F
A
N
C
TOGGLE
SWITCH
TO CONTROL
THERMOSWITCH
A
CRECEPTACLE
L
N
INTERLOCK
THERMOSWITCH
t°
FAN CONTROL
THERMOSWITCH
t°
TERMINAL
STRIP
FRONT
BLUE
RED
BLUE
RED
WHITE
RED
BLACK
BLACK
BLACK
BLACK
BLACK
WHITE
G
RN/YE
L
BLACK YELLOW
BLACK YELLOW
Figure 9 Wiring Diagram
20
Maintenance
Fans When ordering a replacement fan, be sure to specify the model, the
fan part number, ac voltage, and fan position. The fan will be
provided with lugs and leads of the right length for direct attachment
to the terminal block.
+ NOTE: Different fans are used in the 115V and 230V loads. Also,
the fan style depends on its position in the blower; A is in front, B
is in the middle, and C is at the rear, nearest the terminal block.
To replace a fan, follow these instructions:
WARNING
Disconnect the unit from all power sources before servicing.
The unit may be energized from multiple sources.
The potential for electric shock exists.
1. Pull the fan grill out so that its upper flanges come free from the
housing, then pull it down and remove it.
2. On the terminal block, remove the lugs and leads for the defective
fan. All L1 leads go to terminals 5 and 6, and all L2 leads to
terminals 2 and 3.
+ NOTE: It may be necessary to loosen the harness clamps on the
other fans to release the required wires.
3. Remove the four fan mounting screws and remove the fan.
4. Insert the replacement fan in the same position and orientation,
and replace the screws.
5. Connect the leads to the terminal block. All L1 leads go to
terminals 5 and 6, and all L2 leads to terminals 2 and 3.
6. Replace the fan grill.
7. Connect the unit to ac power. Set the switch to MANUAL
momentarily to check that the fans are working properly, then set
it back to AUTOMATIC.
21
Bird 8930 Series Termaline Coaxial Load Resistor
Storage and Shipment
Cover the load before storing to keep out dust and dirt. It is not
necessary to install the shipping plug. Store in a dry, dust-free
environment where the ambient temperature will remain between
–40 and +45 °C (–40 to +113 °F).
To ship the load, take the following precautions:
y Remove the vent plug and install the shipping plug. Wrap the
vent plug with padding and tape it to the side of the load for
protection.
+ NOTE: With the shipping plug installed, it is not necessary to
empty out the coolant.
y Wrap the connector in padding.
y Pack and brace the load in a sturdy wooden crate for shipment.
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: (440) 519-2298
Fax: (440) 519-2326
For the location of the Sales Office nearest you, give us a call or visit
our Web site at:
http://www.bird-electronic.com
22
Specifications
Maintenance
Frequency Range
Power Rating
dc – 1000 MHz
10 kW continuous duty
Peak Power for Pulse Width
1 µs
10 µs
100 µs
1000 µs
5000 µs
Impedance
150 kW
120 kW
85 kW
55 kW
30 kW
50 ohms
VSWR
dc – 400 MHz
400 – 1000 MHz
1.15 max
1.2 max
Connectors
8931
8932
8936
8937
8938
Female LC
1-5/8” EIA Flanged
3-1/8” EIA Flanged
3-1/8” Unflanged
3-1/8” Unflanged, Recessed Center Conductor
*
AC Power
–115
–230
AC Line Power Rating
Fuse Rating
115 Vac
230 Vac
Thermoswitch
Interlock
Fan Control
Thermoswitch Rating
115 Vac
230 Vac
Ambient Temperature
115 V +10, –6% @ 50/60 Hz ±3%
230 V +10, –6% @ 50/60 Hz ±3%
460 W max
IEC (5 x 20 mm) Type T
3.15 A
1.25 A
Normally closed. Opens at 226 °C (439 °F)
Normally open. Closes at 60 °C (140 °F)
10 A
5 A
†
– 40 to +45 °C (– 40 to +113 °F) @ 60 Hz
– 40 to +40 °C (– 40 to +104 °F) @ 50 Hz
23
Bird 8930 Series Termaline Coaxial Load Resistor
Altitude
‡
Humidity
Cooling method
Dimensions
Weight, Nominal
Finish
* Set the duty factor so that the load’s average power rating is not exceeded.
† Derate RF power rating by 100 W for every 1 °C (1.8 °F) above 45 °C (113 °F)
@ 60Hz, or 40 °C (104 °F) @ 50Hz, up to a maximum of 60 °C (140 °F).
‡ Derate RF power by 250 W for every 305 m (1,000 ft.) above 1,520 m
(5,000 ft.), up to a maximum of 3,050 m (10,000 ft.).
1520 m (5000 ft.)
95% noncondensing max
Oil dielectric and forced air convection
7
29
⁄
”L x 9.5”W x 33
8
3
⁄
”H (759 x 241 x 847 mm)
8
142 lb. (64.4 kg)
Grey Powder Coat
24
Replacement Parts
DESCRIPTION QTY PART NUMBER
Maintenance
RF Load Resistor
8931
8932
8936
8937
8938
Resistor O-Ring 1 5-230
Clamping Band Assembly 1 2430-055
Plugs
Vent
Shipping
Interlock Thermoswitch 1 8890-017
Thermoswitch Body 1 8890-015
Thermoswitch Connector Jack 1 2450-018
Control Thermoswitch 1 8892-333
Thermoswitch Body 1 8892-334
Thermoswitch Connector Jack 1 2450-018
Coolant, 5 gal (18.9 L) 1 5-1070-3
Radiator Assembly 1 8921-002
1
8931-117
8932-117
8936-117
8937-117
8938-117
1
2450-094
2450-049
Blower Assembly
115 V
230 V
Blower Control Cable 1 8931-135-2
Blower Fan, 85 W
Fan only, without leads
115 V
230 V
With Leads
115 V, Front (A)
115 V, Middle (B)
115 V, Rear (C)
230 V, Front (A)
230 V, Middle (B)
230 V, Rear (C)
Blower Base Grille Guard 1 8931A106
Side Panel Assembly 2 8931-103
1
8931A101-1
8931A101-2
3
5-740-1
5-740-2
8931A127-1
8931A128-1
8931A129-1
8931A127-2
8931A128-2
8931A129-2
25
Bird 8930 Series Termaline Coaxial Load Resistor
Fuse
115 V, 5 x 20 mm Type T, 3.15 A
230 V, 5 x 20 mm Type T, 1.25A
Neon Lamp
115 V
230 V
Switch, Toggle 1 5A2312
AC Line Supply Cable
115 V
230 V
2
5A2257-21
5A2257-17
1
5A2409-1
5A2409-2
1
8950A023-1
8950A023-2
Available QC Connectors
Connector Part
Number
BNC-Female 4240-125 LT-Female 4240-018 Mini UHF-Female 4240-346
BNC-Male 4240-132 LT-Male 4240-012 UHF-Female 4240-050
C-Female 4240-100 N-Female 4240-062 UHF-Male 4240-179
C-Male 4240-110 N-Male 4240-063 1-5/8” EIA Fixed 4240-096
Connector Part
Number
Connector Part
Number
HN-Female 4240-268 SC-Female 4240-090 1-5/8” EIA Swivel 4240-208
HN-Male 4240-278 SMA-Female 4240-336 7/8” EIA 4240-002
LC-Female
LC-Male 4240-025 7/16 Jack, IEC
Open Term.
# 10-32 Nut
* Normally supplied on the 8931
*
4240-031 SMA-Male 4240-334 TNC-Female 4240-156
4240-344 TNC-Male 4240-160
Type 169-4
4240-080 7/16 Plug, IEC
Type 169-4
4240-363
26
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.
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