QUANTUM™ HD COMPRESSOR CONTROL PANEL
MAINTENANCE
090.040-M (MAR 12)
Page 22
POWER SUPPLY
DESCRIPTION
The power supply of the HD control panel consists of
three independent supplies, and are located on the
inside of the front door below the Interface board.
They supply the following DC voltages:
• +5 VDC
• +12 VDC
• +24 VDC
All three supplies are adjustable and each has a green
LED indicator to show that they are powered. Refer
to the following page for the location for the adjust-
ment.
+5 VDC
Power LED
+12 VDC
Power LED
+24 VDC
Power LED
Power Supplies
POWER DISTRIBUTION
DC power from the power supplies is wired directly
to a series of terminal blocks. The terminals for these
voltages are labeled as follows:
• Common (1000)
• +24 VDC (1001)
• +5 VDC (1003)
• +12 VDC (1004)
+12 VDC power is then distributed to the Q5 processor
board, Interface Board, and Analog I/O boards from
these terminals. +5 VDC is for the Digital board(s),
and +24 VDC is for external as needed control.
MEASURING VOLTAGES
CAUTION! Measuring and adjusting the power sup-
ply voltages require the control power switch to be
energized. Extreme care must be observed when tak-
ing any readings, as 120 or 230 VAC (depending on
incoming system voltage) will be present next to the
DC voltage connector. Adjusting the supplies requires
the use of a small insulated Philips screwdriver in-
serted into the supply to access an adjusting potenti-
ometer. CAUTION: It is possible for the screwdriver
(and the person making the adjustment) to come
into contact with potentially lethal voltages. Prop-
er Personal Protective Equipment (PPE) measures
need to be observed.
All circuit boards within the Q5 control panel require
accurately adjusted DC voltages to function proper-
ly. Periodic measurement and adjustment of the DC
power system is recommended for optimum system
operation. Over time, it is possible for temperature,
humidity, vibration and component age, to degrade
the accuracy of these voltages. When any of the DC
voltages begin to stray from their optimum range,
mysterious problems can begin to arise.
Even with a perfectly adjusted supply, it is possible for
a potential drop in voltage at each connection point.
This drop normally is in the millivolt range, but un-
der some conditions, the drop can be much greater
(as high as tenths of a volt). By the time the volt-
age reaches the last board in the daisy chain, and all
of these potential voltage drops are considered, the
combined drop can be such that problems can be ap-
parent. Some examples of problems could be:
• Loss of or intermittent communications fail-
ures.
• A shutdown message stating Digital Board x
Reset (where “x” is replaced by the number
of the Digital Board that failed).
• An shutdown message stating Analog Board
x Comm. Fail - Shutdown (where “x” is re-
placed by the number of the Analog Board
that failed).
• Numerous sensor fault shutdown messages.
• Q5 reboots for no apparent reason.
• Improper readings of analog pressures and
temperatures.
• LED's on the Q5 are lit, but nothing appears
on the display.
To perform measurements and adjustments on the
power supply voltages, use a reliable, calibrated Digi-
tal Volt Meter (DVM). The DVM should be accurate
to 1/100 of a volt DC. With the control power switch
turned ON, wait until the Operating Screen appears.
This is because the graphics required to create this
screen will draw more current than when the screen
is not fully booted. If the screen never appears how-
ever (possibly due to a voltage problem), you will
need to proceed regardless of what is or is not dis-
played.
In order to properly measure the DC power system,
it must be checked at the DC power terminal strip.
Ensure that the meter is set to the proper range (DC,
0-50 V or equivalent), as well as observing proper
wire polarity. The power supply pictorial shown on
the following page depicts the position of each sup-
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