HEATING & COOLING
30HR,HS070-160
Flotronic Plus Reciprocating Liquid Chillers
Controls Troubleshooting Guide
Alf Model E Units Have Microprocessor Controls
and Electronic Expansion Valves
CONTENTS
SAFETY CONSIDERATIONS
Page
SAFETY
CONSlDERATlONS
................ 1
FLOTRONIC PLUS CONTROL SYSTEM ..... l-4
Generat ..................................... 1
Features .....................................
2
. PROCESSOR MODULE ...................
2
l LOW-VOLTAGE RELAY MODULE .........
2
. EXV
(ELECTRONK
EXPANSION
VALVE) DRIVER MODULE ...............
2
. KEYBOARD AND DISPLAY MODULE .....
2
. ELECTRONIC EXPANSION VALVE ........
3
l THERMISTORS ...........................
3
. CAPAClTY CONTROL ....................
3
CONTROL SEQUENCE .....................
4,5
Off Cycle ....................................
4
Start-Up ....................................
4
Capacity Control ............................
4
l SEQUENCE ...............................
4
Unit Shutdown ..............................
5
Complete Unit Stoppage
.....................
5
Single-Circuit Stoppage .....................
5
Lag Compressor Stoppage ...................
5
Restart Procedure ...........................
5
l GENERAL POWER FAlLURE ..............
5
l BLOWN FUSE
IN
POWER FEED
DISCONNECT ............................
5
l LOW WATER TEMPERATURE
CUTOUT..................................
5
l AUXILIARY INTERLOCK .................
5
l OPEN CONTROL
CIRCUlT
FUSE ..........
5
. FREEZE PROTECTION ....................
5
a HIGH-PRESSURE SWITCH ................
5
l LOSS OF CHARGE SWITCH ...............
5
. COMPRESSOR DISCHARGE
TEMPERATURE SWITCH .................
5
. OIL SAFETY SWITCH .....................
5
CONTROLS OPERATION .................. .5-l I
Accessing Functions and Subfunctions. ......
5
Qisplay Functions ...........................
5
a SUMMARY DISPLAY .....................
5
. STATUS FUNCTION ......................
5
. TEST FUNCTION ........................
10
Programming Functions
....................
1
I
.
SERVlCE
FUNCTION ....................
11
l SET POINT FUNCTION ..................
11
l SCHEDULE FUNCTION ..................
11
TROUBLESHOOTING .....................
12-26
Checking Display Codes ....................
12
l OPERATING MODE CODES ..............
12
. ALARM CODES
.........................
12
Quick Test .................................
14
Electronic Expansion Valves ................
19
l CHECKOUT PROCEDURE ...............
19
l EXV OPERATION ........................
21
Thermistors ................................
22
l LOCATION ..............................
22
l SENSOR REPLACEMENT ................
22
Modules ....................................
23
Installation, start-up and servicing of this equipment
can be hazardous due to system pressures, electrical
components and equipment location.
Only trained, qualified installers and service mechanics
should install, start-up and service this equipment.
When working on the equipment, observe precautions
in the literature, tags, stickers and labels attached to the
equipment and any
other
safety precautions that apply.
l Follow all safety codes.
0
Wear safety glasses and work gloves.
l Use care in handling, rigging and setting bulky
equipment.
l Use care in handling elcetronic components.
ELECTRII~ SHOCK HAZARD.
Open all remote disconnects before
servicing this equipment.
This unit uses a micreprocessor-based electronic
control system.
190
not use jumpers or other tools
to short out components, bypass or otherwise depart
from recommcndcd procedures. Any short-to-
ground of the control board or accompanying wiring
may destroy the electronic modules or electrical
component.
FLOTRONIC PLUS CONTROL SYSTEM
General
-
The 30HR,HS Flotronic Plus chillers
feature microprocessor-based electronic controls and an
electronic expansion valve (EXV) in each refrigeration
circuit.
The Flotronic Plus control system cycles compressors
and compressor unloaders to maintain the selected leav-
ing water temperature set point. It automatically positions the EXV to maintain the specified refrigerant
superheat entering the cylinders of the compressor.
Safeties are continuously monitored to prevent the unit
from operating under unsafe conditions. A scheduling
function, programmed by the user, controls the unit
occupied/ unoccupied schedule. The control also operates
a Quick Test program that allows the operator to check
input and output signals to the microprocessor.
The control system consists of a processor module
(PSIO), low-voltage relay module (DSIO), electronic
expansion valve (EXV), EXV driver module (DSIO),
keyboard and display module (HSIO) and thermistors to
provide analog inputs to the microprocessor. The soft-
ware resides in the PSIO.