Johnson Controls Frick QUANTUM Series Maintenance Manual page 46

090.560-M (APRIL 13)
Page 46
and position 6 connects to ground (GND) of the external
device for channel 2, as shown below:
Channel 1
Channel 1
Signal
Each input channel is confi gurable through the operating
software. There are twenty-four analog input channels
that can be selected for 4-20 mA, 0-5 Vdc, ICTD, or RTD.
Besides properly setting the software confi guration, each
channel is setup through software calibration for the
proper transducer type and range, and each transducer
must be calibrated through the appropriate sensor
calibration screen. Improper setup of either the hardware
or software will result in incorrect operation or range.
The most common fault associated with the improper
reading of the analog channels other than hardware or
software setup problems fall into one of the following
categories:
• Sensor fault
• Wiring problem
• Improper grounding of system.
An open wire, shorted wire, or faulty sensor will usually
give a reading at either the minimum or maximum end of
the range scale. An erratic reading or a reading that seems
to fl oat up and down is usually indicative of a grounding
problem. When a single transducer or cable is shorted to
earth (or system) ground, this can show up as a whole
assortment of problem channels. The easiest way to fi nd
a short to earth problem is to disconnect all the sensor
plugs and ohm out each plug screw terminal to earth for
open (infi nite) impedance. All sensors should read open to
earth. The third pin on pressure sensors is ground.
REPLACING A DEFECTIVE ANALOG BOARD
The procedure to replace an Analog board is outlined
below:
1. Ensure that all channel confi guration information
for the board being replaced has been written
down.
2. Shut off control power.
3. Unplug all connectors from the board.
4. Remove the old board from the unit and remove
the new board from its packing and place both
on an anti-static surface.
QUANTUM™ LX CONDENSER/VESSEL CONTROL PANEL
Channel 2 + Channel 2
GND
Signal
GND
MAINTENANCE
5. Check
components are properly setup on the new
board using the old board as a reference (refer
to the Analog Settings tables near the end of this
section).
6. Install the modifi ed replacement board in the
panel.
7. Plug all connectors back in.
8. Turn on control power.
9. After the panel has rebooted, access the Analog
Board Confi guration Setup screen, and re-enter
the correct channel confi guration. The default
setup of the new board will be loaded to the
processor. It is imperative that the channel
confi guration screen be accessed to ensure that
the channels are confi gured properly for the
application.
After replacing or installing an Analog Board and powering
on the control panel, select User Level 1 or higher, then
select the Setpoints Menu, then the Communications
Menu. On the Communications Screen is a button labeled
as [Redetect I/O Comms]. Clicking on the [Redetect I/O
Comms] button will cause the controller to examine the
internal I/O communications of the panel, and initialize
all connected boards If a board has been removed, a
communication error shutdown will be issued until this
key is selected. The About screen will show what was
detected.
that all jumpers, dipswitches and