Replacing The Pressure Control And Circuit Board - Graco EM 390 Instructions And Parts List

REPLACING THE PRESSURE CONTROL & CIRCUIT BOARD
WARNING
To reduce the risk of serious bodily injury, including
fluid injection or splashing in the eyes or on the
skin, or injury from moving parts, always follow the
Pressure Relief Procedure Warning on page 16
before checking, adjusting, cleaning or shutting off
the sprayer. Unplug the power supply cord.
NOTE: A circuit board (23f) is not included with a new
pressure control (50). However, it is included with
a new motor and it can be ordered separately.
Be sure to order the correct circuit board. See the
application information on page 26.
CAUTION
Do not allow the fittings (A) to move when removing
the elbow (312) or nipple (313) from the pressure
control, to avoid altering the factory setting of the
pressure control or damaging the pressure control.
Circuit Board Removal
1. Remove the pressure control cover (41). Pull the cir-
cuit board (23f) out carefully, just enough to reach the
wire terminals. Disconnect the leads. Remove the
board. See Fig 23–1.
Pressure Control Removal
2. Disconnect the hose (52). See Fig 23–2.
3. Disconnect the remaining two motor leads (black and
green/yellow). See Fig 23–1.
4. Remove the screws (7). See Fig 23–2 .
5. Pull the pressure control (50) away from the conduit
(1) and carefully guide the leads through the connec-
tor (303) one at a time. See Fig 23–1.
6. Remove the mounting bracket (40). Remove the fit-
tings (302, 312, and 313). Remove the fluid filter (47).
Install these parts on the new pressure control. See
Fig 23–2.
Pressure Control Installation
7. Guide the motor leads into the new pressure control.
8. Position the circuit board in the pressure control so
the wire connectors are at the top. Connect the leads
to the board. Guide the leads into the pressure con-
trol, making sure they don't catch on anything. Slide
the board into place.
9. Connect any other loose wires. See Fig 23–1.
23
13
1
TRIAC
LEADS
WHITE
RED
WHITE
50
Fig 23–1
47
Fig 23–2
10. Mount the pressure control on the cart.
11. ADJUST THE PRESSURE CONTROL! See page 24.
WARNING
Adjust the pressure control whenever a new or
used pressure control or circuit board is installed,
to reduce the risk of overpressurization which can
result in component rupture, fire or explosion. Im-
proper adjustment may also prevent the sprayer
from obtaining the maximum working pressure, re-
sulting in poor sprayer performance.
MOTOR
LEADS
BLACK
GREEN & YELLOW
RED
PINK
BROWN
303
23c
23f
GREEN
BLACK
WHITE
POWER
SUPPLY
LEADS
41
0749
40
50
41
A
312
313
302
7
52
0677