Emerson 7003M - Manual (Page 44)

Operator Manual
748223-K
June 2002
3-18 Operation Rosemount Analytical Inc. A Division of Emerson Process Management
Model 7003M
c. Relay Contacts
Relay contacts are listed in Table 3-18 below:
TERMINAL LOCATIONS
RELAY POS
ALARM1 ALARM2
NO (Normally open) TB3-3 TB3-6
NC (Normally closed) TB3-2 TB3-5
COM (Common) TB3-1 TB3-4
Relay positions are with power removed.
Table 3-18. Alarm Relay Contact Positions/Terminal Locations
d. Fail Safe Operation
The relays are setup to operated in "Fail
Safe" configuration. In this configuration
the relay coils are powered when the unit
is NOT in an alarm condition. When an
alarm condition occurs, power is removed
from the relay coils.
If a power failure occurs, power will be
removed from the relays and an alarm
condition will be indicated to the device
connected to the relays.
e. Relay Reset Upon Fatal Error
If a fatal error is detected, the unit will
attempt to reset itself which will make
both relays go into alarm mode. If the
microprocessor is able to continue its
operation, the relays will then be reset to
their normal operating position.
f. Pressure Effects on Alarms
If the sample pressure changes, the
partial pressure of oxygen, and thus the
reading, will change and the alarm relays
will not actuate at the same oxygen levels
as they were set when the interment was
last calibrated. See Section 5-2a on page
5-1 for a more detailed description of
pressure effects.
g. Setting Alarm and ON/OFF-Controller
Relays
Wherever "Alarm" is referred to in this
section, the term "ON/OFF-Controller" can
be substituted, unless specifically called
out. Also, any reference to A1 or Alarm 1
also applies to Alarm 2, and to ON/OFF-
Controllers 1 and 2.
h. Setting Alarm Setpoints
This procedure can be used to:
• Verify alarm relay setpoints
• Change setpoints
• Enable alarms
• Disable alarms
Perform the following procedure for each
Alarm setpoint, as required. Figure 3-6
illustrates how relays are energized and
de-energized in High and Low Alarm
configurations.