Carrier 30GTN Installation Instructions Manual page 10

Demand Limit (Switch Controlled) —
plied pair of dry contacts can be used to provide one or two
steps of demand limit. The dry contacts must be connected to
TB6. Connect the contacts for Demand limit step one to
TB6-12, 13. Connect the contacts for Demand Limit step two
to TB6-14, 15. This is a step function which will limit the over-
all chiller capacity to pre-configured percentages when the
switch contacts close. Follow the steps outlined in Table 4 to
enable the function and configure a demand limit of 70% for
step one and 40% for step two.
Table 4 — Menu Configuration of Demand Limit Mode (Switch Controlled)
MODE KEYPAD
(RED LED) ENTRY
CONFIGURATION
ENTER
A field-sup-
KEYPAD
SUBMODE ITEM
ENTRY
DISP
UNIT
OPT1
OPT2
RSET CRST
ENTER
CRT1
CRT2
DGRC
DMDC
ENTER
ENTER
ENTER
DMDC
ESCAPE
DM20
SHNM
SHDL
SHTM
DLS1
ENTER
ENTER
ENTER
DLS1
ESCAPE
DLS2
ENTER
ENTER
ENTER
DLS2
ESCAPE
10
The configuration is now complete. The overall chiller ca-
pacity (CAP, under the Run Status mode, submode VIEW) will
now be reduced to 70% when Demand Limit switch 1 is
closed. The capacity will be further reduced to 40% when De-
mand Limit switch 2 is closed. The actual demand limit switch
inputs seen by the control can be viewed by accessing the items
DLS1 and DLS2, located under the Inputs mode, submode
GEN.I.
DISPLAY ITEM EXPANSION
0
125
0
0
DEMAND LIMIT
0
SELECT
0
0
1
1
DEMAND LIMIT
1
SELECT
100
0
0
60
DEMAND LIMIT
80
SWITCH 1
80
80
70
70
DEMAND LIMIT
70
SWITCH 1
DEMAND LIMIT
50
SWITCH 2
50
50
40
40
DEMAND LIMIT
40
SWITCH 2
COMMENTS
SCROLLING STOPS
FLASHING '0'
SELECT '1'
CHANGE ACCEPTED
ITEM/VALUE/UNITS
SCROLLING RETURNS
SCROLLING STOPS
FLASHING '80'
SELECT '70'
CHANGE ACCEPTED
ITEM/VALUE/UNITS
SCROLLING RETURNS
SCROLLING STOPS
FLASHING '50'
SELECT '40'
CHANGE ACCEPTED
ITEM/VALUE/UNITS
SCROLLING RETURNS