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824-000

15 

Intermediate Problem Solving

TYPE OF PROBLEM

WHAT TO CHECK
If check is OK, go to next check

WHAT TO DO
When check is not OK, refer to this column

Low output

 

(continued)

3. Release gun trigger. Observe resting position of

pump rod (107).

3. If pump consistently comes to rest with

rod (107) fully extended, the piston pack-
ings and/or piston valve may be worn.
Service the pump. See page 21.

4. Check electrical supply with volt meter. Meter

should read 105–125VAC.

4. Reset building circuit breaker; replace

building fuse. Repair electrical outlet or
try another outlet.

5. Check extension cord size and length; must be

at least 12 gauge wire and less than 150 ft 
(45 m) long.

5. Replace with a correct, grounded exten-

sion cord.

6. Check motor brushes. See Electrical – What To

Check, item 4, on page 13.

6.  See page 19.

7. Check motor start board (47) by substituting

with a good board.

CAUTION: Do not perform this check until mo-
tor armature is determined to be good. A bad
motor armature can burn out a good board.

7. Replace board. See page 26.

8. Check motor armature for shorts by using an

armature tester (growler) or perform motor test.
See page 17.

8. Replace motor. See page 25.

Drain valve leaks

1. Check drain valve for correct torque and/or

worn parts. Check for debris trapped on seat.

9. Tighten to 185 in–lb (21 N.m). Clean

valve and replace with new gasket (42a)
and sealant (42d). See page 32.

Transducer leaks

1. Slight leakage from transducer is normal.

1. Periodically remove residue from its cyl-

inder port. See page 30.

No output: motor runs and
pump strokes

1. Check paint supply.

1. Refill and reprime pump.

2. Check for clogged intake strainer.

2. Remove and clean, then reinstall.

3. Check for loose suction tube or fittings. See

page 31.

3. Tighten; use thread sealant on npt

threads of adapter (38).

4. Check to see if intake valve ball and piston ball

are seating properly. See page 21.

4. Remove intake valve and clean. Check

ball and seat for nicks; replace as need-
ed. See page 21. Strain paint before us-
ing to remove particles that could clog
pump.

5. Check for leaking around throat packing nut

which may indicate worn or damaged packings.
See page 21.

5. Replace packings. See page 21. Also

check piston valve seat for hardened
paint or nicks and replace if necessary.
Tighten packing nut/wet-cup.

6. Release gun trigger. Observe resting position of

pump rod (107).

6. If pump consistently comes to rest with

rod (107) fully extended, the piston pack-
ings and/or piston valve may be worn.
Service the pump. See page 21.

No output: motor runs but
pump does not stroke

1. Check displacement pump connecting rod pin

(17). See Fig. 17, page 21.

1.  Replace pin if missing. Be sure retainer

spring (18) is fully in groove all around
connecting rod.

7. Check connecting rod assembly (15) for dam-

age. See page 27.

7. Replace connecting rod assembly. See

page 27.

8. Be sure crank in drive housing rotates; plug in

sprayer and turn on briefly to check. Turn off
and unplug sprayer. See page 27.

8. Check drive housing assembly for 

damage and replace if necessary. See
page 27.

Summary of Contents for Nova Plus 824-002

Page 1: ...Maximum Working Pressure Model 824 002 Series A Complete sprayer with hose gun RAC IV DripLess Tip Guard and SwitchTip The SHERWIN WILLIAMS COMPANY CLEVELAND OHIO 44115 COPYRIGHT 1995 GRACO INC This...

Page 2: ...alerts you to the possibility of damage to or destruction of equipment if you do not follow the instructions FIRE AND EXPLOSION HAZARD Improper grounding poor ventilation open flames or sparks can cau...

Page 3: ...also cause serious injury Fluid injected into the skin is a serious injury The injury may look like just a cut but it is a serious injury Get immediate medical attention Do not point the gun at anyon...

Page 4: ...80 F or below 40 C 40 F Do not lift pressurized equipment Comply with all applicable local state and national fire electrical and safety regulations WARNING WARNING INSTRUCTIONS Liquids can be injecte...

Page 5: ...sprayed through spray gun G 50 ft 15 m Main Hose 1 4 in ID grounded nylon hose with spring guards on both ends H RAC IV Tip Guard Reverse A Clean RAC tip guard reduces the risk of fluid injection inj...

Page 6: ...up 1 3 full with Graco Throat Seal Liquid TSL supplied Install the wet cup seal 3 Plug in the sprayer Be sure the ON OFF switch 52 is OFF Plug the cord into a 15A grounded outlet at least 20 feet away...

Page 7: ...p If the valve senses an over pressure condition it opens automati cally to relieve fluid pressure If this happens stop spraying immediately shut off and unplug the sprayer Determine the cause of the...

Page 8: ...e Fig 6 Clean the front of the tip frequently during the day s operation First follow the Pressure Relief Procedure on page 9 Fig 6 Tip handle shown in spraying position Turn handle 180 trigger gun to...

Page 9: ...fter following the steps above VERY SLOWLY loos en the tip guard retaining nut or hose end coupling to relieve pressure gradually then loosen completely Now clear the tip or hose obstruction Startup P...

Page 10: ...9 Engage the gun safety latch 10 Install the spray tip and tip guard Install the spray tip If you are using the RAC IV tip guard refer to manual 307 848 for installation instruc tions 11 Adjust the sp...

Page 11: ...y 100 hours of operation Remove the front cover Fill the bearing housing cavity A with SAE 10 non detergent oil See Fig 10 5 Flush the sprayer at the end of each work day and fill it with mineral spir...

Page 12: ...screen Clean the screen separately 3 Pour one half gallon 2 liters of compatible solvent into a grounded metal flushing pail Put the suction hose in the pail 4 Open the pressure drain valve See Fig 4...

Page 13: ...ce and secure with spring retainer 3 Check for motor damage Remove drive hous ing assembly 11 See page 27 Try to rotate motor fan by hand 3 Replace motor 4 if fan won t turn See page 25 Electrical 1 C...

Page 14: ...witch and connect volt meter between exposed terminal on switch and power cord s white wire Plug in sprayer and turn ON Meter should read 105 125VAC Turn off and unplug sprayer 10 Replace ON OFF switc...

Page 15: ...kage from transducer is normal 1 Periodically remove residue from its cyl inder port See page 30 No output motor runs and pump strokes 1 Check paint supply 1 Refill and reprime pump 2 Check for clogge...

Page 16: ...all wires 2 Check for missing motor brush inspection plate gasket see page 17 bent terminal forks or other metal to metal contact points which could cause a short 2 Correct faulty conditions 3 Check...

Page 17: ...the motor fan by hand If there are no shorts the motor will coast two or three revolutions before coming to a complete stop If the motor does not spin freely the armature is shorted and the motor must...

Page 18: ...before operating the sprayer WARNING HOT SURFACE HAZARD During operation the motor and drive housing become very hot and could burn your skin if touched Flammable materi als spilled on the hot bare m...

Page 19: ...ut the spring clip See Fig 14 3 Slide off the brush lead terminal E off the blade connector Remove the old brush C See Fig 14 Fig 14 F G E D C B H 1 1 Motor lead do not disconnect 2 Minimum 0 5 12 5 m...

Page 20: ...eed d Inspect the brush and commutator contact area for excessive arcing Arcs should not trail or circle around the commutator surface WARNING MOVING PARTS HAZARD Do not touch the brushes leads spring...

Page 21: ...Loosen the screws 21 Remove the pump 20 Installing the pump See Fig 16 and 17 1 Mount the pump on the drive housing Tap it into the alignment pins with a soft hammer Tighten the screws 21 to 50 ft lb...

Page 22: ...open end wrench to loosen the nut 110 and then unscrew the piston valve 108 7 Remove all parts from the piston valve 108 Reassembling the pump NOTE Alternate plastic and leather packings See Fig 18 T...

Page 23: ...to avoid damaging the packings by overtightening 6 Hand tighten the valve into the piston rod just until the nut 110 contacts the rod See Fig 20 7 Place the flats of the rod 107 in a smooth jaw vise 8...

Page 24: ...98 N m Torque cylinder 115 into manifold 101 to 53 ft lb 71 N m Torque intake valve 116 into cylinder 115 to 53 ft lb 71 N m Piston assembly 14 Place the ball guide 120 stop pin 122 and ball 121 in t...

Page 25: ...Remove the three drive housing screws and lockwashers 19 6 Also see Fig 25 6 Remove the two motor screws 5 and the lock washers 6 7 Tap the lower rear of the drive housing 11 with a plastic mallet to...

Page 26: ...ws 56 and lower the junction box 59 3 Disconnect the power supply cord leads including the green wire to the grounding screw 49 4 Loosen the strain relief bushing 51 Remove the power supply cord 50 5...

Page 27: ...lose the thrust balls 11a or 4a or let them fall between the gears which will damage the drive housing if not removed The balls which are heav ily covered with grease usually stay in the gear re cesse...

Page 28: ...Connecting Rod Crankshaft 02840 Fig 28 Torque to 80 in lb 9 N m Quantity of three Quantity of one Apply a total of 3 fl oz 29 cc of grease to gears 56 6 19 15 13 64 11 5 6 12a 12 12b 59 11a 4a A 34 31...

Page 29: ...d tip the pressure control 64 forward and up to detach it from the drive housing 11 4 Guide the harness A through the motor and drive housing and remove the pressure control 5 Guide the harness of the...

Page 30: ...21 2 Use a pull twist motion to remove the transducer 29 from the pump manifold 101 3 Clean paint residue from the hole in the manifold do not scratch the surface of the hole 4 Lightly apply oil to th...

Page 31: ...A threads will engage and the hose will separate from the tube 3 Replace the o ring 27 if it is worn or damaged 4 Lubricate the o ring 27 and the inlet tube 38 threads with light grease 5 Align the s...

Page 32: ...seat area 2 If replacing the gasket 42a or seat 42b pry out the gasket NOTE Whenever the gasket 42a is removed re place it with a new one 3 Coat the o ring 42d with grease Press the stem into the valv...

Page 33: ...20 292 V PACKING plastic piston 3 113 820 280 V PACKING leather piston 2 114 820 463 GLAND female piston 1 115 820 979 CYLINDER pump 1 116 820 617 PACKING o ring PTFE 1 117 820 972 NUT jam 1 3 8 18 un...

Page 34: ...18 15 16 45 37 29 32 25 12b 12a 64 30 5 19 6 17 31 34 21 38 36 46 4 39 28 56 43 42 42a 42b 4e 44 REF 32 REF 33 11 23 63 67 74 42c 42d 11b 14 4g INSIDE LABEL 35 OUTSIDE LABEL 4f See detail on page 35 2...

Page 35: ...97 SUCTION HOSE TUBE 1 33 820 898 DRAIN HOSE 1 34 820 899 SCREW filh 8 32 x 2 1 2 3 35 820 249 LABEL identification 1 36 820 900 ADAPTER tube 9 16 18 1 37 820 901 LEG sprayer 2 38 820 902 INLET TUBE 1...

Page 36: ...damage or wear caused by faulty installation misapplication abra sion corrosion inadequate or improper maintenance negligence accident tampering or substitution of non Graco component parts Nor shall...

Page 37: ...One of 4c changed to 4g 820 439 4c WIRE terminal Replaced by 820 446 18 AWG Quantity changed to one Other Changes Add the following data to the Technical Data section of your instruction manual Sound...

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