30GXN,R080-528
30HX076-271
Minimum Load Control Accessory
50/60 Hz
Installation Instructions
Part No. 30GX-900---048,
(60 Hz — 115-v Control)
Part No. 30GX-900---049
(50 or 60 Hz — 230-v Control)
CONTENTS
IMPORTANT: When removing refrigerant, use an
approved refrigerant recovery device. Do not vent refrig-
erant into the atmosphere.
Page
SAFETY CONSIDERATIONS. . . . . . . . . . . . . . . . . . . . . . 1
INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Step 1 — Examine Package Contents . . . . . . . . . . . . 1
Step 2 — Install Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
• REMOVE MINIMUM LOAD PORT PLUGS
AND INSTALL FITTINGS
INTRODUCTION
The minimum load control accessory allows 30HX and
30GXN,R chillers to have their capacities decreased below the
standard fully unloaded condition. The accessory provides
more precise control of leaving fluid temperature during light
load conditions.
The 30GXN,R and 30HX chillers have a dual-circuit
design. Each minimum load control accessory package con-
tains the items required for both circuits. Because of an auto-
matic lead/lag feature on the chillers, the accessory should be
installed on both circuits.
• INSTALL PIPING
• INSTALL BALL AND SOLENOID VALVES
• CONNECT PIPING
• 30GXN,R UNITS ONLY
Step 3 — Dehydrate and Recharge Circuit. . . . . . . . 3
Step 4 — Install Control Wiring. . . . . . . . . . . . . . . . . . . 3
• 30HX UNITS
• 30GXN,R UNITS
• ALL UNITS
Step 5 — Configure Unit for Minimum
Load Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Step 6 —Test Minimum Load Relay
Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Step 7 — Adjust Setting of Minimum
Load Ball Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
INSTALLATION
Step 1 — Examine Package Contents — Pack-
age includes solenoid valves, ball valves, O-ring seal fittings,
and instructions. Examine each item. If any part is damaged or
missing, file a claim immediately with the shipper and notify
your Carrier representative. See Table 1 for accessory package
contents and field-supplied material.
SAFETY CONSIDERATIONS
Table 1 — Accessory Package Contents
and Field-Supplied Material
Installing, starting up, and servicing air-conditioning equip-
ment can be hazardous due to system pressures, electrical com-
ponents, and equipment location.
Only trained, qualified installers and service technicians
should install, start up, and service this equipment.
When working on air-conditioning equipment, observe pre-
cautions in the literature and on tags, stickers, and labels
attached to the equipment.
ACCESSORY PART NUMBER
ACCESSORY PACKAGE
COMPONENTS
30GX-900---048
(2) EF23JX212
(2) EP71BA201
(4) 30GX503492
(2) 30GX503487
30GX-900---049
(2) EF23JX231
(2) EP71BA201
(4) 30GX503492
(2) 30GX503457
Solenoid Valve
Ball Valve
O-Ring Seal Fitting
Tube Assembly
Tube Assembly (Condenser
Oil Separator)
(2) 30HX402343
(2) 30HX402343
Follow all safety codes. Wear safety glasses and work
gloves. Use care in handling equipment.
FIELD SUPPLIED MATERIAL — REQUIRED PARTS
(Ordered Separately)
5/8-in. OD Copper Tubing, Wiring, Conduit,
Field Supplied
Thread Sealant, Electrical Supplies
Be sure power to equipment is shut off before performing
maintenance or service.
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 1 102 7-00 Replaces: 30GX,HX-7SI
Book 2
Tab 5c
Fig. 2 — Installing Fittings and Valves, 30HX (Typical)
30GXN,R UNITS ONLY — Using good brazing practice,
codes and NEC (National Electrical Code, U.S.A.). Wire size
must be no. 16 AWG (American Wire Gage) (1.5 mm2) mini-
mum. See Fig. 4 and 5 for field wiring.
30HX UNITS — Remove the screws holding the right-side
access panel to the unit control box. Open the right-side access
panel.
Route wires through field-supplied conduit and attach the
conduit to the unit control box, using a suitable conduit fitting
and one of the available 7/8-in. knockout openings. Attach the
other end of the conduit to the solenoid valve, using a suitable
fitting. Repeat for the other circuit. See Fig. 4.
braze the 5/8-in. minimum load tubing to the copper nipple on
the discharge line (minimum load port) between the condenser
coil and oil separator. See Fig. 1, 3A and 3B.
Step 3 — Dehydrate and Recharge Circuit —
When piping has been completed, leak test the assembly. If
one of the O-ring seal fittings leaks, slowly tighten the O-ring
nut until the leak stops. If this does not fix the leak, the connec-
tion must be reinstalled using a new O-ring in the fitting. Con-
tact your Carrier representative for assistance in locating these
parts.
30GXN,R UNITS —Route the field-supplied water proof con-
duit from the solenoid valves to the control box at the end of
the unit. See Fig. 4 and 5.
ALL UNITS — Using good wiring practice, connect a white
wire from the solenoid valve on circuit A to a white wire from
the solenoid valve on circuit B. Connect both wires to TB2-9
(30HX) or TB4-2 (30GX).
After leak testing, evacuate, dehydrate, and recharge the cir-
cuit using an approved refrigerant recovery device. Correct
type and amount of refrigerant are listed on unit nameplate and
in base unit documentation.
Step 4 — Install Control Wiring
Connect a pink wire to the solenoid valve on circuit A.
Connect a gray wire to the solenoid valve on circuit B. Con-
nect both the pink and gray wires to TB5-9 for all units.
Be sure all power to the unit is off before proceeding. Lock
out and safety-tag all disconnects.
Figure 4 shows the correct location of the wiring connection
points on the chiller.
Wires between field-installed components and unit control
box must be enclosed in field-supplied conduit. Follow all local
3
MINIMUM LOAD
CONTROL PORTS
SOLENOID VALVE (TYP)
BALL VALVE (TYP)
CIRCUIT A (080-138)
CIRCUIT B (150, 160)
O-RING SEAL FITTING
AND ADAPTER (TYP)
CIRCUIT B (080-138)
CIRCUIT A (150, 160)
→
Fig. 3A — Typical Piping and Valve Installation 30GXN,R080-178
and Associated Modular Sizes (080-150, 160 Shown)
SEE DETAIL C
O-RING SEAL
FITTING
SOLENOID
VALVE
DETAIL C
FIELD INSTALLED
PIPING TO
CIRCUIT B DISCHARGE
LINE
BALL
VALVE
MINIMUM LOAD PORT
CIRCUIT B
MINIMUM LOAD PORT
CIRCUIT A
FIELD INSTALLED PIPING
TO CIRCUIT A DISCHARGE LINE
→
Fig. 3B — Typical Piping and Valve Installation 30GXN,R204-350
and Associated Modular Sizes (204-268 Shown)
102
4
30GXN,R080-178*
MLC-B
CONDUIT
MLC-A
CONDUIT
30HX076-186
LEGEND
C
—
—
—
Contactor Compressor
Circuit Breaker
GND
LR
—
—
—
—
—
—
—
Ground
SPT
—
Suction Pressure
Transducer
CB
CCP
Loader Relay
ComfortLink™ Compressor
Protection
MLC
OPC
PL
Minimum Load Control
Oil Pump Contactor
Plug Assembly
Primary
Screw Compressor
Board
Sensor (Toroid)
TB
TRAN
—
—
Terminal Block
Transformer
CLHR
EMM
EQUIP
EXV
—
—
—
—
—
—
—
Cooler Heater Relay
Energy Management Module
Equipment
Terminal Block Connection
PRI
SCB
Unmarked Splice
Factory Wiring
Electronic Expansion Valve
Fuse Block
FB
SN
—
FR
Fan Relay
GFI-CO
Ground Fault Interrupter Convenience Outlet
*And associated modular sizes.
Fig. 4 — Typical Minimum Load Control Wiring
→
5
102
MLC-B
CONDUIT
MLC-A
CONDUIT
30HX206-271
30GXN,R204-350*
*And associated modular sizes.
→
Fig. 4 — Typical Minimum Load Control Wiring (cont)
102
6
Fig. 4 — Typical Minimum Load Control Wiring (cont)
ROUTE CONDUITS THROUGH TRAY
AND ATTACH TO BOTTOM OF SHELF
ON TB-4 SIDE OF CONTROL BOX
Fig. 5 — Routing Field-Supplied Wiring and Conduit (30GXN,R Shown)
7
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.
ENTER
6. Press the
display reads:
MLV ON
and
key to energize the relays. The
An audible click will be heard. Verify that the solenoid
valves for both circuits are energized.
ESCAPE
1. Press
key until display reads ‘SELECT A MENU
ENTER
ENTER
7. Press the
,
and
keys to turn the solenoids
ITEM.’ Press
key to light up Configuration mode.
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.
ENTER
Press
Press
. Press key to select sub-mode ‘OPT1’.
ENTER
.
After testing is complete, recheck all electrical connections
for proper location and tightness. Replace and secure the access
panels for the unit control box.
2. Press the down arrow
key to select MLVS NO.
3. To enable the minimum load valve feature, press the
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.
ENTER
key.
4. The display may read as follows. (If not, skip to Step 7.)
ENTER PASSWORD
ENTER
5. Press 1 1 1 1 then
key.
6. The Navigator again displays the following:
MLVS NO
ENTER
7. Press
MLVS YES
The chiller is now configured for minimum load valve
key and The Navigator displays:
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:
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.
ESCAPE
1. Press the
key until the Navigator displays ‘SE-
LECT A MENU ITEM.’ Press the
key and light up
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.
ENTER
ENTER
the Service Test mode. Press the
key. Press the
key and ‘TEST OFF’ will be displayed with ‘OFF’ flash-
ENTER
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
ENTER
3. Press 1 1 1 1 then
key.
key to select the ‘COMP’ sub-
key and key to display MLV
4. Press the down arrow
Once the outputs have been tested and the ball valve ad-
justed, the installation is complete.
ENTER
mode. Press the
OFF.
ENTER
5. Press the
key.
Copyright 2000 Carrier Corporation
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
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