Model FF-1600 with out Heat
18
17942C-1, Issue 1
4.
LEAKING INLET CHECK VALVE - An inlet check valve and/or leaking seat that
does not properly seal will permit some of the proportioned material to flow back
towards the supply drum. When this happens the proper volume of material will not
pump during the discharge stroke and an off-ratio condition will result.
5.
A 2200-psi pressure limit switch protects each Proportioning Pump. Upon reaching
this pressure, the switch automatically removes power from both directional valves
causing the pump to stall. When the power is removed, both Directional Indicator
Lights will go out, this indicates there has been an over-pressure shutdown.
This is not a lockout type of system and when the pressure bleeds off to
approximately 200 psi, the Proportioning Pumps will be restored to normal
operation; however, the cause of the over-pressure should be determined first and
then corrected.
The most likely causes of over-pressure are:
a)
Restriction in the gun
b)
Pump cavitation
c)
Air pressure set too high
6.
CONTROL TRANSFORMER FUSE - With the power OFF, open the electric
console, and remove the control transformer fuse. Check it for continuity or simply
replace it.
WARNING:
R
EPLACE THE FUSE WITH ONE OF THE SAME RATING
. A
SUBSTITUTE MAY
DAMAGE THE EQUIPMENT AND WOULD CREATE A POTENTIAL SOURCE OF INJURY TO THE
OPERATOR
.
WARNING:
B
EFORE PERFORMING THESE TROUBLE SHOOTING PROCEDURES DETERMINE
THAT ALL CIRCUIT BREAKERS ARE OFF AND MAIN POWER IS DISCONNECTED AT THE SOURCE TO
AVOID SEVERE BODILY INJURY FROM ELECTRICAL SHOCK
. D
O NOT ENTER THE ELECTRICAL
CONSOLE WITH THE POWER ON
7.
REVERSING SWITCH - In order for the Proportioning Unit to switch direction or
reverse, the ends of a slot machined in the rear leg of the pump yoke must contact the
arm of the switch lever. This contact causes the switch lever to activate on the
reversing switch, which energizes one air valve coil and de-energizes the other. A
problem arises when the yoke fails to contact the switch lever or when the spool in
the air valve fails to shift after its coil activates.
Typically, something physically prevents the yoke from traveling its full stroke. In
this case physically check and correct it. It may also be the result of the air pressure
set to a point where the total resistance downstream of the air motor is such that the
air motor cannot pump against it. Correct this by simply increasing the air pressure.
8.
ROLLER BEARINGS- Occasionally replacing the roller bearing is necessary if they
become clogged with dirt or Isocyanate and seize.
9.
UPSTROKE REGULATOR- During the upstroke, both Proportioning Pumps will be
on the fill stroke and will receive a boost from the supply pump pressure. Adjust the
upstroke regulator so the Proportioning Pump speeds are equal on both strokes.
