Carrier 30GXN - Manual (Page 8)

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 903 Catalog No. 533-00009 Printed in U.S.A. Form 30GX,HX-14SI Pg 8 102 7-00 Replaces: 30GX,HX-7SI Book 2
Tab 5c
Copyright 2000 Carrier Corporation
Step 5 — Configure Unit for Minimum Load
Control —
Once the piping installation and wiring installa-
tion are complete, the chiller must be configured for minimum
load control operation. This may be done using the Navigator.
Set the Enable/Off/Remote/Contact switch in the OFF position.
1. Press key until display reads ‘SELECT A MENU
ITEM.’ Press key to light up Configuration mode.
Press . Press key to select sub-mode ‘OPT1’.
Press .
2. Press the down arrow key to select MLVS NO.
3. To enable the minimum load valve feature, press the
key.
4. The display may read as follows. (If not, skip to Step 7.)
ENTER PASSWORD
5. Press 1 1 1 1 then key.
6. The Navigator again displays the following:
MLVS NO
7. Press key and key. The Navigator displays:
MLVS YES
The chiller is now configured for minimum load valve
control.
Step 6 — Test Minimum Load Relay Out-
puts —
After the accessory components are installed and the
unit is recharged and reconfigured, test the operation of the re-
lay and solenoid valve using the Service Test software func-
tion. Test both circuits as follows:
1. Press the key until the Navigator displays ‘SE-
LECT A MENU ITEM.’ Press the key and light up
the Service Test mode. Press the key. Press the
key and ‘TEST OFF’ will be displayed with ‘OFF’ flash-
ing. Press the key then key and the Navigator
displays ‘TEST ON.’ Switch the Enable/Off/Remote
contact switch to the Enable position.
2. The display may read as follows. (If not, skip to Step 4.)
ENTER PASSWORD
3. Press 1 1 1 1 then key.
4. Press the down arrow key to select the ‘COMP’ sub-
mode. Press the key and key to display MLV
OFF.
5. Press the key.
6. Press the and key to energize the relays. The
display reads:
MLV ON
An audible click will be heard. Verify that the solenoid
valves for both circuits are energized.
7. Press the , and keys to turn the solenoids
off. When finished, exit the Service Test mode (change
‘TEST ON’ to ‘TEST OFF’). Put the Enable/Off/Remote
Contact switch in the desired position.
After testing is complete, recheck all electrical connections
for proper location and tightness. Replace and secure the access
panels for the unit control box.
Step 7 — Adjust Setting of Minimum Load Ball
Valve —
Before the installation is complete, the minimum
load ball valve must be adjusted to suit the application. Cali-
brate one circuit at a time as follows:
1. Adjust the ball valve so that it is approximately half open.
2. Operate the chiller in Service Test mode, with one circuit
operating, and all compressor loaders deenergized.
NOTE: Operation of the chiller in Manual Control mode is
described in the Controls, Start-Up, Operation, and Trouble-
shooting Guide that is included with the 30GXN,GXR,HX
ComfortLink™ chillers.
3. Record the cooler
∆T (the difference between cooler en-
tering fluid temperature and cooler leaving fluid tempera-
ture) at this fully unloaded condition.
4. Use the Service Test feature to enable the minimum load
valve output.
5. Observe and record the cooler
∆T with the minimum load
valve energized.
6. Adjust the minimum load ball valve until the cooler tem-
perature difference reading from Step 5 is equal to half of
the temperature difference reading from Step 3.
7. Open the ball valve to decrease the temperature differ-
ence or close the ball valve to increase the temperature
difference (
∆T). When the valve is adjusted correctly, the
difference between cooler entering and leaving fluid tem-
peratures when the minimum load control is energized
must be at least half of the temperature difference when
the minimum load control is deenergized. For example, if
the difference between the cooler entering and leaving
water temperature is 3° F with the valve deenergized,
then the difference between cooler entering and leaving
water temperature must be at least 1.5° F with the valve
energized.
Once the outputs have been tested and the ball valve ad-
justed, the installation is complete.
ESCAPE
ENTER
ENTER
ENTER
ENTER
ENTER
ESCAPE
ENTER ENTER
ENTER
ENTER
ENTER
ENTER
ENTER
ENTER ENTER