Emerson Liqui-tect MC68HC16Z1 - Manual (Page 35)

System and Control Options
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6.5.1 Specify Longest Cable Length
You may specify the length of the longest cable connected to either of the 4-20mA alarm outputs. The
default value is 0-1000 ft. (0-304.8m). Valid entries range from 0-500 ft. (0-152.4m) to 0-5000 ft.
(0-1524m), as shown in the Maximum Cable Length screen, below right.
Select the longer cable length installed on either zone. For example, if Zone 1 has 2000 ft. (609.6m) of
cable and Zone 2 has 3500 ft. (1066.8m), select 0-4000 ft. (0-1219.2m).
The chosen setting applies to both zones and is correlated to the 4-20mA output of each zone to pro-
vide the distance of the leak. Once the range is selected, the following correlation will be applied:
5mA = 0 ft. (0m)
19mA = 4000 ft. (1219.2m)
Table 10 shows the operation of the 4-20mA outputs.
To specify the maximum cable length:
• From the Maximum Cable Length screen, below right, use the
arrows ↑↓ to choose the correct range—for example,
0-4000FT(0-1219.2M).
• Press Enter ↵ .
6.5.2 Define Relays as Normally Open or Normally Closed
All four digital alarm outputs may be set up as Normally Open (NO) or
Normally Closed (NC). The default setting is NO (Normally Open). The
chosen setting applies to all cable fault/contamination and leak relays
for both zones.
To change the normal state:
• From the Normally Open / Closed screen, below right, use the
arrows ↑↓ to choose NO (Normally Open) or NC (Normally Closed).
• For a non-supervised mode, select Normally Open. The
relays energize for an alarm condition.
• For a supervised mode, select Normally Closed. The relays
de-energize for an alarm condition or loss of power.
• Press Enter ↵ .
6.5.3 Define Alarms as Latched or Unlatched
All four digital alarm outputs may be set up as Latched (Y) or
Unlatched (N). When configured as Latched, alarms must be manually
reset by an operator after they are cleared, as described in 6.9 - Reset
Latched Alarms. The default setting is Latched (Y). The chosen set-
ting applies to cable fault and leak relays for both zones.
To change this setting:
• From the Latched / Unlatched screen, shown at right, use the
arrows ↑↓ to choose Y (Latched) or N (Unlatched).
• Press Enter ↵ .
Table 10 Operation of 4-20mA outputs
Signal Operation
0mA Indicates cable cannot be monitored
4mA Indicates normal operation
5mA 0 ft. (0m)
19mA Longest cable length (ft.)—for example, 4000 ft. (1219.2m)
20mA Indicates cable fault / contamination
Setup System Menu
SETUP ZN1 ZONE 1
SETUP ZN2 ZONE 2
> SETUP ALARM OUTPUTS
↑↓
=NEXT
↵
=SELECT
SETUP REALARM DELAY
SETUP MAPMODE
SETUP SYSTEM INFO
Maximum Cable Length
SELECT LONGEST
CABLE CONNECTED
> 0-500FT (0-152.4 M)
↑↓
=NEXT
↵
=SELECT
0-1000FT (0-304.8M)
0-1500FT (0-472.2M)
0-2000FT (0-609.6M)
0-2500FT (0-762.0M)
0-3000FT (0-914.4M)
0-4000FT(0-1219.2M)
0-5000FT(0-1524.0M)
Normally Open / Closed
ARE LEAK & FAULT
RELAYS NORMAL OPEN
OR NORMAL CLOSED? NO
↑↓
=NO/NC
↵
=END
Latched / Unlatched
IS LEAK & FAULT
ALARM LATCHED? Y
↑↓
=Y/N
↵
=END