Maintenance Mode Operation - Graco PGM Instructions - Parts Manual

Maintenance Mode Operation

Operating from maintenance mode enables the pump to
begin dispensing when the user presses
Dispense parameters and duration depend on the
selected control.
Verify System Operation
Use maintenance mode to manually check the operation
of the PGM system components before switching over
to automation control (normal operation).
NOTE: Perform any of the following procedures
while in maintenance mode.
Set Inlet Pressure
The inlet pressure reading should be in the range of
300 psi (2.1 MPa, 21 bar) to 1500 psi (10.3 MPa,
103 bar). The recommended inlet pressure should be
500 psi (3.4 MPa, 34 bar) lower than the outlet pres-
sure.
Follow steps in the supply system manual to set the inlet
pressure.
Excessive inlet pressure will cause accelerated wear
on the gear meter seals and the pump feed system.
Feed System Pressure Drop
During material flow, the PGM inlet pressure decreases.
The amount the pressure decreases is the amount of
pressure lost between the feed pump and the PGM inlet.
With high viscosity fluids, long line lengths, or small
diameter line sizes this pressure decrease can be thou-
sands of psi (hundreds of bar). This means that the
static pump pressure is set much higher than the PGM
needs at its inlet. To prevent excessive static pressure
at the inlet of the PGM, a dynamic regulator is recom-
mended on air motor supply air. During dispense the
normal pump regulator is active. During a stalled condi-
tion the dynamic regulator is active.
3A5185B
NOTICE
Dispense Weight Verification
1. From maintenance screen, select Shot mode.
2. Enter a 10 second shot time.
.
3. Enter the desired flow rate.
4. Record a minimum of 5 shot weights.
5. If shot weights are inconsistent check feed pressure
or reduce flow rate and repeat shot test.
NOTE: Regular weight checks are recommended to
ensure system is performing properly.
Operation
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