Insulation Tests; No-Load Current Values - Hitachi DH 24PM Technical And Service Manual

B. Additional wiring work
General internal wiring can be accomplished by referring to
paragraphs 9-4 and 9-5-A. The following are special
instructions for switch connection.
(1) Wiring of reversing switch
Insert the lead wire (black) coming from the stator into
the terminal (4) of the reversing switch, and the lead wire
(white) into the terminal (3) as shown in Fig. 36.
Insert the lead wire (brown) coming from the carbon
brush or choke coil into the terminal (2) and the lead wire
(blue) into the terminal (1). After insertion, pull each lead
wire slightly to check that the lead wires do not come off.
To disconnect the lead wires, insert a small flat-blade
screwdriver into the windows near the terminals and pull
out the lead wires.
(2) Wiring of speed control switch
Insert each cord into the terminal 1 and terminal 2 of
the speed control switch as shown in Fig. 37 and tighten
the screw [tightening torque: 0.6
5.2 1.7 in-lbs.)]. Insert the lead wire (gray) coming
from the stator into the terminal M1 and the lead wire
(red) into the terminal M2. Insert each lead wire (white)
coming from the noise suppressor into the terminal C1
and C2.
After insertion, pull each lead wire slightly to check the
lead wires do not come off. To disconnect the lead wires,
insert a small flat-blade screwdriver into the windows
near the terminals and pull out the lead wires.

9-6. Insulation Tests

On completion of disassembly and repair, measure the insulation resistance and conduct the dielectric strength
test.
Insulation resistance: 7 M Ω or more with DC 500 V megohm tester
Dielectric strength: AC 4,000 V/1 minute, with no abnormalities 220 V --- 240 V (and 110 V for U.K. products)
AC 2,500 V/1 minute, with no abnormalities 110 V --- 120 V (except U.K. products)

9-7. No-load Current Values

After no-load operation for 30 minutes, the no-load current value should be as follows:
Voltage (V)
Current (A) max.
0.2 N m (6
•
110 120
3.6 3.3
Fig. 36 Wiring of reversing switch
2 kgf cm,
•
Fig. 37 Wiring of reversing switch
220 230
1.8 1.7
--- 37 ---
240
1.6