OWNER’S MANUAL
© 1999 MILLER Electric Mfg. Co.
January 1999 FORM: OM-178 715A
4:1 Impedance Matching Transformer 043276
1. Specifications
4:1 Turns Ratio; Step Down Transformer
10 To 50 kHz Output Frequency Range
Reflective Impedance is approximately 16 Times Coil Impedance
70% Duty Cycle At Rated Primary Amperage
70% Duty Cycle At Rated Primary Amperage
1.3 qt/min (1.2 L/min) Minimum Coolant Flow Rate (Built-In Flow Indicator For Checking Coolant Flow)
70 kVA Rating
Length: 12 in (305 mm); Width: 8-3/4 in (222 mm); Height: 6-1/4 in (159 mm)
801 415-A
Weight: Net 18-3/4 lb (8.5 kg)
2. Safety Symbol Definitions
Warning! Watch Out! There are possible hazards as shown in the adjoining symbols.
Beware of electric shock from wiring. Keep all panels and covers closed.
Induction heating can cause fire. Move flammables away. Do not overheat parts and adhesive. Watch for fire; keep extinguisher
nearby.
Breathing fumes and gases from induction heating operations can harm your health. Properly ventilate work area. Read Material
Safety Data Sheets (MSDS’s) and manufacturer’s instructions for materials used.
Hot parts can cause burns. Induction heating makes parts very hot − let them cool before touching. Do not touch or handle induc-
tion head during operation. Keep metal jewelry and other metal personal items away from head during operation.
Wear safety glasses with side shields.
Have only trained and qualified persons install, operate, or service this unit. Call your distributor if you do not understand the direc-
tions. For INDUCTION HEATING SAFETY and EMF information, read power source manual.
Beware of moving parts. Keep guards and panels in place, covers closed, and hands away from moving parts.
Recycle or dispose of used liquids in an environmentally safe way. This is especially true for engine fluids such as drain oil and
used coolant; also important for coolant from cooling systems.
OM-178 715 Page 2
3. Connecting Transformer To Power Source
ST-801 049
1 Output Receptacle RC15
2 Plug From Transformer
3 Threaded Collar
Receptacle RC15 is a 4-socket
receptacle.
To connect to receptacle, align key-
way, insert plug, and tighten
threaded collar.
4 14-Socket Receptacle
1
Power Source Rear Panel
2
3
4
4. Connecting Coolant Lines To Transformer
801 415-A
1 Coolant In Fitting
2 Coolant Out Fitting
Connect lines from coolant system
to correct fittings on transformer.
Install induction coil using the sup-
plied O-rings and bolts.
3 Flow Indicator (166 559)
4 Flow Switch Receptacle
Connect flow switch receptacle to
14-socket receptacle on rear of
power source (see Section 3).
Turn on coolant flow and power
source, and check for any coolant
leaks. Check coolant flow at flow in-
dicator on transformer.
If power source contactor does not
energize, flow switch is not closed.
Check coolant system for proper
flow through transformer.
Tools Needed:
1
2
4
3
5. Operation
Install & Connect
Power Source
Put On
Personal Safety
Equipment
Set
Controls
Turn On
Power
Switch
Wait
10 Seconds
Unit Ready
To Heat
Turn On
Coolant Supply
Position Work
Near
Heat Station
Install & Connect
Transformer &
Install & Connect
Coolant Supply
Induction Coil
OM-178 715 Page 3
6. Routine Maintenance
Y Disconnect power before maintaining.
3 Months
Clean And
Tighten Output
Connection
(see Section 3)
Water Hose
Replace
Cracked
Parts
Output
Cord
6 Months
Replace
Unreadable
Labels
Blow Out Or
Vacuum Inside.
During Heavy
Service,
Clean Monthly
OR
7. Troubleshooting
Trouble Remedy
No heat output. Connect power source to proper input voltage or check for low line voltage (see power source Owner’s
Manual).
Transformer coolant flow switch not closed. Check coolant system for proper flow through transformer.
No heat output; fan motor continues to
run.
Tuning capacitor cover safety interlock switch open (see power source Owner’s Manual).
Secure transformer plug in power source receptacle (see Section 3).
Thermostat TP1 open (overheating). Allow fan to run; the thermostat will close when the unit has cooled
(see power source Owner’s Manual).
Low heat output. Check tuning of induction heating output system (see Section 8).
8. Tuning Chart
CAUTION
ENERGIZING CONTACTOR WITHOUT ALL 3 TUNING CAPACITORS IN OUTPUT CIRCUIT will damage pow-
er source.
• DO NOT operate power source without all 3 tuning capacitors in output circuit.
Voltage* Current (Amperage)* Frequency (KHz) Corrective Action
High Low Low Lower inductance or decrease matching transformer turns ratio
High Low High Add capacitance
High Low Mid-Range Decrease matching transformer turns ratio and add capacitance
Low High Low Lower capacitance
Low High High Increase matching transformer turns ratio, or lower capacitance and
increase inductance
Low High Mid-Range Increase matching transformer turns ratio and lower capacitance
*High voltage > 300 V rms; Low voltage < 200 V rms; Operating current range: 0 to 210 A rms
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