Marvair MAR7000, Product Data Sheet

Page: 17 / 22

MAR7000 17 1/2013, P/N 01757 Rev. B
Troubleshooting
Alarm Issues
Alarm, (False) Fan Fail
• Check configuration. Be sure the Fan Status
option is not selected when there is no sensor/
switch for it.
• Check that the IN2 (fan status) input pull-up
resistor switches are fully latched in the correct
positions. Any passive, dry contact should use
the 10K Ohm setting. (See Input Connections
on page 5 .)
• Check IN2 (fan status) input wiring.
• Check the connected fan status sensor/switch.
Alarm, (False) Space Temp. or Humidity
• See Alarms on page 14 .
• See Temperature Reading Is Incorrect on page
18 .
• See Temperature Setpoint Is Not Maintained
on page 19 .
Cover, Display, and Reset Issues
Cover Binds on Backplate
• Be sure top and bottom tabs are both pushed
in when removing the cover.
• Carefully remove the MAR7000 cover from
the backplate and inspect for bent pins and/
or terminal socket connectors. If cover pins
are bent, use a needle-nose pliers to straighten
them. If socket connectors are bent, use
a pointed object (such as a thumbtack or
straightened paperclip) to straighten them.
(Pushing the pointed object into the socket
from the back side can be helpful.)
• When installing the cover, it may be helpful to ap-
ply more pressure toward the bottom of the cover.
• Replace the backplate.
NOTE: When installing the cover on the
backplate, be sure to not pinch or
dislodge any wiring. Do not use
excessive force. If there is any binding,
pull out cover and examine pins and
terminal socket connectors.
Display Is Blank (or Erratic)
• If the display comes on when a button is
pushed, Display Blanking is enabled. (See
System Setup on page 16 .)
• Carefully remove the MAR7000 cover from
the backplate, check pins and connectors, and
reinsert. (See Cover Binds on Backplate on
page 17 .)
• Check for a tripped circuit breaker to the
transformer.
• Check for proper supply voltage from the
transformer and that the transformer has
enough capacity (VA) for all connected devices
(see their respective specifications).
NOTE: Wiring must be adequate to avoid
excessive voltage drop on long runs!
Allow plenty of “cushion.” A meter
may be too slow to register transient
dips or peaks during startup. See Wiring
Issues on page 20 .
• Put another MAR7000 on the installed
backplate, and if the second MAR7000
functions properly, replace the first MAR7000.
• See also Display Keeps Resetting on page 18 .