Hitachi UC 14YFA Manual

TECHNICAL DATA
AND
SERVICE MANUAL
CHARGER
UC 14YFA
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
LIST No. F888 Aug. 2003
U
MODEL
UC 14YFA
Hitachi 
Power Tools

Page
CONTENTS
1. PRODUCT NAME........................................................................................................................1
2. MARKETING OBJECTIVE ..........................................................................................................1
3. APPLICATIONS...........................................................................................................................1
4. SELLING POINTS .......................................................................................................................2
4-1. Selling Point Descriptions ........................................................................................................... 3
5. SPECIFICATIONS .......................................................................................................................6
5-1. Specifications.............................................................................................................................. 6
5-2. Comparisons with Similar Products ............................................................................................ 6
6. PRECAUTIONS IN SALES PROMOTION ..................................................................................7
6-1. Safety Instructions ...................................................................................................................... 7
6-2. Extra Precautions in Sales Promotion ........................................................................................ 8
7. QUESTIONS AND ANSWERS ON MODEL UC 14YFA .............................................................9
8. GENERAL PRECAUTIONS ......................................................................................................12
8-1. Model UC 14YFA ...................................................................................................................... 12
8-2. Pilot Lamp Indications............................................................................................................... 12
9. PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY .......................................................13
9-1. Disassembly ............................................................................................................................ 13
9-2. Reassembly .............................................................................................................................. 13
9-3. Confirmation after Reassembly ................................................................................................ 13
10. TROUBLESHOOTING GUIDE ................................................................................................14
10-1. Troubleshooting Based on Pilot Lamp Indications.................................................................. 14
10-2. Troubleshooting and Repair Procedures ................................................................................ 14
11. STANDARD REPAIR TIME (UNIT) SCHEDULES...................................................................18
Assembly Diagram for UC 14YFA

1
1. PRODUCT NAME
Hitachi Charger, Model UC 14YFA
2. MARKETING OBJECTIVE
As the cordless tool market expands strongly, customers have come to expect low-price chargers. The new
Model UC 14YFA is based on the current Model UC 24YFA and low-price by limiting the rechargeable batteries to
Hitachi major batteries. This is capable of recharging both nickel cadmium (Ni-Cd) and nickel metal hydride
(Ni-MH) batteries from 7.2 V to 14.4 V rapidly.
3. APPLICATIONS
Recharging of Hitachi batteries
Applicable batteries:
EB 712S [7.2 V, 1.2 Ah]
EB 912S [9.6 V, 1.2 Ah]
EB 1212S [12 V, 1.2 Ah]
EB 1412S [14.4 V, 1.2 Ah]
EB 7S [7.2 V, 1.3 Ah]
EB 9S [9.6 V, 1.3 Ah]
EB 12S [12 V, 1.3 Ah]
EB 914 [9.6 V, 1.4 Ah]
EB 1214 [12 V, 1.4 Ah]
EB 1414 [14.4 V, 1.4 Ah]
EB 9B [9.6 V, 2.0 Ah]
EB 12B [12 V, 2.0 Ah]
EB 14B [14.4 V, 2.0 Ah]
EB 1220BL [12 V, 2.0 Ah]
EB 9M [9.6 V, 2.0 Ah]
EB 12M [12 V, 2.0 Ah]
EB 924 [9.6 V, 2.4 Ah]
EB 1224 [12 V, 2.4 Ah]
EB 1424 [14.4 V, 2.4 Ah]
EB 9H [9.6 V, 2.2 Ah]
EB 12H [12 V, 2.2 Ah]
EB 14H [14.4 V, 2.2 Ah]
EB 1222HL [12 V, 2.2 Ah]
EB 930H [9.6 V, 3.0 Ah]
EB 1230H [12 V, 3.0 Ah]
EB 1230HL [12 V, 3.0 Ah]
EB 1430H [14.4 V, 3.0 Ah]
Ni-Cd batteries*
Ni-MH batteries
* The Model UC 14YFA can also recharge the B-2 and B-3 batteries by means of the adaptor for the Model
UC 14YF2.

2
EB 7S
EB 712S
EB 9S
EB 914
EB 9B
EB 9M
EB 924
EB 9H
EB 930H
EB 912S
EB 12S
EB 12B
EB 12M
EB 1224
EB 12H
EB 1230H EB 1414
EB 14B
EB 1424
EB 14H
EB 1430H
EB 1412S
EB 1214L
EB 1220BL
EB 1222HL
EB 1230HL
EB 1212S
General purpose charger capable of
recharging 7.2 V to 14.4 V batteries
4. SELLING POINTS
(1) Accepts both Ni-MH and Ni-Cd batteries
(2) Rapidly charges all Hitachi EB-series batteries
Charging time:
1.2 to 1.4 Ah •••••••• 30 minutes 2.2 Ah ••••••••••••••••• 55 minutes 3.0 Ah ••••••••••••••••• 70 minutes
2.0 Ah ••••••••••••••••• 50 minutes 2.4 Ah ••••••••••••••••• 60 minutes
(3) Hitachi original charge control mechanism for longer battery life
Easy-to-read visual display of charging
status through constant lighting or flashing
of red and green pilot lamps
Fig. 1
3-way overcharging
protection systems
for longer battery
and charger life
Capable of recharging both nickel cadmium (Ni-Cd) and nickel
metal hydride (Ni-MH) batteries
Recharging/discharging cycles of battery
(ambient temperature range between 10˚C and 30˚C)
•Ni-Cd: about 1,000 times
•Ni-MH: about 500 times
Capable of recharging batteries with internal temperatures
as high as 60˚C (nickel cadmium (Ni-Cd) batteries)

3
4-1. Selling Point Descriptions
4-1-1. Capable of handling both nickel cadmium (Ni-Cd) and nickel metal hydride (Ni-MH) batteries
Through application of HITACHI-microcomputer and electronic-circuit control technology, Model UC 14YFA is
capable of handling both Ni-Cd and Ni-MH batteries.
4-1-2. Recharging/discharging cycles of battery (ambient temperature range between 10 ˚C and 30 ˚C)
•Ni-Cd battery: about 1,000 times
•Ni-MH battery: about 500 times
Recharging/discharging cycles of batteries can be dramatically increased by stopping recharging just before the
overcharging range by means of the system or the dT/dt system. (Refer to 4-1-4 for details.)
4-1-3. Capable of recharging batteries with internal temperatures as high as 60 ˚C
Each nickel cadmium (Ni-Cd) battery shown in Figs. 2 and 3 incorporates a thermistor. The Model UC 14YFA can
continue recharging these batteries until the battery temperature reaches 60 ˚C.
(Note 1) •Wiring diagrams for batteries are shown below.
•The thermistor is an element to detect the battery temperature.
•The 95 ˚C thermal protector incorporated in each 14.4 V battery interrupts the recharging circuit
when the battery temperature reaches 95 ˚C.
•The discriminating resistor is incorporated in each nickel metal hydride (Ni-MH) battery to distinguish
them from the nickel cadmium (Ni-Cd) batteries.
•Because the nickel metal hydride (Ni-MH) batteries are heated to high temperatures during
recharging, this charger operates within a range of 10˚C temperature difference between the
maximum battery temperature when starting recharging (45 ˚C) and the temperature when stopping
recharging (55 ˚C).
Thermistor
Fig. 2 Ni-Cd batteries (7.2 to 12 V)
Thermostat
Terminal
+
Terminal
S
Terminal
--
Thermistor 95 ˚C Thermal protector
Terminal
--
Terminal
+
Terminal
--
Terminal
S
(Terminal positions)(Terminal positions) Fig. 3 Ni-Cd batteries (14.4 V)
(Terminal positions) (Terminal positions)
Fig. 4 Ni-MH batteries (9.6 to 12 V)
Terminal
T
Fig. 5 Ni-MH batteries (14.4 V)
Terminal
+
Terminal
S
Terminal
--
Thermistor
Discriminating
resistor
Terminal
--
Terminal
+
Terminal
S
Terminal
--
Terminal
T
95 ˚C Thermal protector
Terminal
T
Thermistor
Discriminating
resistor