Alpha Tool.Com.HK Limited Polisher WDP120 User Manual

21
		PERIODIC
 
  WARNING!
Preventive	maintenance	preformed	by	unauthorized	personnel	may	result	in	mis-
placing	 of	 internal	 wires	 and/or	 components	 which	 voids	 the	 warranty	 and	 could	
cause	serious	hazards.		We 	recommend	that	tool	service	and	repairs	not	covered	
in	the	manual	be	preformed	by	an	Alpha
®	Repair	Center.
Periodic	maintenance	is	done	to	check	the	tool	and	to	minimize	down	time.		These	
checks	are	done	based	on	hours	of	operation	and	operating	conditions.		 Operating	
condition...

22
 REAR	COVER	REMOVAL
1.	 Gently	 pull	 water	 tube	 away	 from	holder.
2.	 Release	the	tube	from	the	holder.
3.		 Unwrap	3	inches	of	the	coiled	 harness.
4.		 Remove	 the	2	screws	 from	the	valve 	
bracket.
Figure-22
Figure-23
Figure-24
Figure-25 

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5.	 Pull	the	valve	assembly	away	from	mount.
6.	 Remove	the	rear	case	screw.
7.		 Hold	 polisher	with	one	hand	 and	
pull 	the 	rear 	case	 straight 	back	 with	
the	other	hand.
NOTE:	 Do	 not		twist	 case	 in	 a	 side	 to	 side	motion	when	pulling	back.
8.	 Pull	 back	the	rear	 case	 until	the	
carbon	 brush	assembly	 is	exposed.
NOTE:	 Do	not	 pull	 rear	 case	 further	 back
from	this	point.
Figure-28
Figure-29
Figure-27
Figure-26 

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9.		 Lift	the 	spring 	from 	the 	
carbon	brush	and	place	on	
the	 side	 of	the	 brush	 holder.
10.	 Remove	 the	carbon	 brush	wire	spade	 connector	 from	the	terminal	 post	and	then 	
remove	the	carbon	brush.
Figure-31
Carbon	Brush
Carbon	Brush Holder
Carbon	Brush Wire
Spring
Figure-30
Figure-32
Spade 	Connector
Figure-33 

11.	 You	can	also 	remove 	the 	carbon 	brush 	by 	
removing	 the	screw	 and	pulling	 the	holder 	
out	with	a	pair	of	needle	nose	pliers.
12.	 With	 the	 carbon	 brush	 holder	 removed,	 you	 can	check	and	clean	the	armature	commuta-
tor.		The	 commutator	 is	the	 contact	 points	that	
the 	carbon 	brushes	 ride	on	when	 the	motor 	is 	
running.
NOTE:  Each polisher has 2 carbon brushes located on opposite sides of  each other.  After the replacement of the two brushes, assemble the 
polisher by...

26
16.	 The	commutator	should	be	clean	and	shiny;	if	it	is	dull	and	black,	you	can	clean	it	with	a	commutator	cleaning	stone.
17.	 To	 clean	the	commutator,	 press	the	commutator	 cleaning	stone	against	 the	com -
mutator	and	rotate	the	armature	by	turning	the	spindle	shaft	by	hand.		 Continue	
for	a	minute	or	until	commutator	is	clean	and	shiny.
18.	 Reconnect	the	power	wire,	ensuring	that	the	wire	path	is	correct.			Reinstall	the	 carbon	 brush	 holder	 into	 the	 slot	 on	 motor	 housing	 and	 slide...

27
ALPHA® WDP-120 SCHEMATIC 
Revised: 12/2013 

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ALPHA® WDP-120 GUARD SCHEMATIC
Optional AccessoryFlexible	Connector	Hose 

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ALPHA® WDP-120 GUARD SCHEMATIC
  DRAWING	NO. PART	NO. DESCRIPTIONQUANTITY
1 310025Output	Shaft	with	Nitriding	(5/8"-11) 1
2 210006Key	(3x10) 2
3 210001Screw	M4x14 4
4 210002Spring	Washer	M4 8
5 210003Plane	Washer	M4 4
6 310002Aluminum	Gear	Case	Cover 1
7 210010Ball	Bearing	6201 1
8 310003Bearing	Cover 1
9 310004Screw	M4x10 3
10 310005Gear	Washer 1
11 210016Gear 1
12 210017Wave	Spring	Lock	Washer	10 1
13 210018"C"	Clip	for	Shaft	10 1
14 210019Oil-impregnated	Bearing	8x12x8 2
16...

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ALPHA® WDP-120 PARTS LIST 
DRAWING	NO. PART	NO. DESCRIPTIONQUANTITY
38 210042Field	Coil	120V 1
39 310015Brand	Label 1
40 210091Field	Coil	Case 1
41 310006Data	Label 1
42 210046Carbon	Brush	Holder 2
43 210047Coil	Spring 2
44 210048Carbon	Brush	120V 2
45 210049SST	Self-tapping	Screw	ST2.9×8 4
46 210094Terminal	Block 1
47 210093Speed	Pot	w/Speed	Feed	Back	Sensor	120V 1
48 210053Rear	Cover 1
49 210054Self-tapping	Screw	4.2x14 3
50 210055Cord	Jacket 1
51 210056Twist	Strip 1
52 210057Rubber	Washer 1
53...