Cornelius Quest 2000 Service Manual page 14

Quest 2000 Service Manual
PROBLEM
Brix Problem
Pump Inoperative
Machine continues to
dispense after dis-
pense button is
released or dis-
penses without opera-
tor input
Publication Number: 720529901SER
PROBABLE CAUSE
• Water supply pressure too low,
less than 20 psi (1.4 bar) flowing
water pressure fluctuates sharply
• Water flow control binding or
spring is defective
• Improperly thawed concentrate.
Brix changes as the concentrate
temperature changes (concentrate
becomes thinner as temperature
rises)
• Pump motor defective
• No power to transformer or no
28VAC output from transformer
• Defective voltage regulator board
(VRB) located inside front electrical
box
• Defective dispense control board
(Push button or portion control)
• Push button or portion control pad
stuck in on position
• Relay on voltage regulator board
(VRB) stuck on.
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REMEDY
• Correct water supply problem to
ensure a constant 50 psi (3.5 bar)
flowing to the dispenser
• Clean and/or replace parts as nec-
essary
• Concentrate should be 35-40°F
(1.7-4.5°C) prior to loading
• 28VDC should be present at pump
motor during dispense. If voltage is
present and motor does not start,
replace pump motor
• Confirm transformer has line volt-
age present on primary side. If no
28VAC output from the secondary
replace transformer
• Confirm board produces 28VDC
present when the dispense button is
pressed (refer to the Electrical Box
Wiring Diagram for VDC output loca-
tion). Replace VRB if necessary
• Test and replace if necessary
• Disconnect the wire harness from
the rear of the portion control and
close the door. If unit does not dis-
pense on its own the dispense con-
trol board is bad (stuck on)
• Disconnect the 4-wire harness
from the lower right corner of the
VRB. If the unit continues to dis-
pense on its own the VRB is defec-
tive (relay stuck on)
© 2004, IMI Cornelius Inc.