Enviro VB09-36, Установка, эксплуатация и обслуживание

Страница: 30 / 40

FORM ET145.18-IOM1 (115)
ENVIRO-TEC 30
12. MAINTENANCE
Maintenance on the unit is simplified with the following
preventive suggestions:
1. Visually inspect unit at least once a month. Special
attention should be paid to hose assemblies. Note any
signs of hose deterioration or cracking; attend to any
indication of minor leakage immediately.
2. Filter maintenance must be performed to ensure proper
operation of the equipment. Inspect filters at least every
three months, and replace when visible dirt build-up is
evident.
To avoid fouled machinery and extensive unit clean
up, DO NOT operate units without filters in place, or
use the unit as a temporary cooling/heating source
during construction.
3. Inspect condensate drain pan for algae growth and
mineral build-up every three months. Excessive algae or
mineral deposits in the drain pan or drain line can result in
condensate overflow and unpleasant mildew odors.
4. Check fan motor and blower assembly annually. All units
employ permanently lubricated fan motors. DO NOT OIL
FAN MOTORS. Vacuum any accumulation of dirt from
motor ventilation slots and the blower wheel.
5. Check the contactors and relays within the control panel
annually. Inspect for any visible signs of overheated
contacts or temperature damage to wiring. Check
terminals for tightness.
6. Conduct an amperage check annually on the compressor
and fan motor. Higher amperage draw than nameplate
values (more than 10%) may indicate heat exchanger
fouling, low water flow, or premature physical motor
failure.
7. Inspect air-to-refrigerant heat exchanger surface at least
once a year. A dirty or partially clogged coil can
significantly reduce operating capacity, and can result in
serious equipment problems. If the coils appear dirty,
clean them using mild detergent or a commercial coil-
cleaning agent.
8. Inspect hoses, valves and connections for water leaks.
For hose connection leaks inspect rubber hose gaskets
and replace as required.
Safety Control Reset
All VSCS heat pumps are furnished with a high-pressure
protection switch, a low-pressure control switch, low water
temperature protection switch and condensate overflow switch
to prevent compressor operation during abnormal conditions.
If either of these safety devices is activated a lockout relay
circuit is engaged, which interrupts heating and cooling
operation, even though the control contacts may have
automatically re-closed.
This microprocessor driven lockout circuit must be manually
reset. Reset is accomplished by moving the thermostat control
(system) switch to the OFF position momentarily, then back to
the HEAT, or COOL (or AUTO) position.
The lockout circuit may also be reset by opening and closing
the unit mounted disconnect switch.
If the unit must be reset more than twice on
consecutive operating cycles, check the unit for a
dirty filter, abnormal entering water temperature,
inadequate or excessive water flow, or refrigerant
circuit malfunction. If the unit continues to cutout,
contact a trained service technician.
13. UNIT CONTROLS
The control system microprocessor board is specifically
designed for water source heat pump operation. The control
system interfaces with a conventional type thermostat.
A. Unit shall be complete with self-contained low-voltage
control circuit
B. Unit shall incorporate a lockout circuit which provides
reset capability from a hard lock-out at the space
thermostat or base unit, should any of the following
standard safety devices trip and shut off compressor.
a. Loss-of-charge/Low-pressure switch
b. High-pressure switch
c. Freeze-protection thermostat, u nit shutdown on low
water temperature .
d. Condensate Overflow protection switch
C. Unit shall operate with conventional thermostat designs
and have a low voltage terminal strip for easy hook-up.
D. Unit control board shall have on-board diagnostics and
fault code display.
E. Standard controls shall include anti-short cycle and low
voltage protection
F. Control board shall monitor each refrigerant safety switch
independently.
G. Control board shall have random start feature
H. Control board shall retain last 5 fault codes in non volatile
memory which will not be lost in the event of a power
loss.
Sequence of Operation
The room t-stat makes a circuit between “R” & “Y1” for cooling.
The call is passed to the unit micro processor control, which
then determines whether the requested operation is available
and, if so, which components to energize.
For the heating, the room t-stat makes a circuit between “R” &
“W1”. The micro processor control energizes the compressor
and fan allowing the unit to run in heating mode.
If at any time a call for both heating and cooling are present,
the heating operation will be performed. If operating, the
cooling system is halted as with a completion of a call for
cooling. Heating always takes priority.
Continuous Blower
With the room t-stat fan switch set to “AUTO” and the system
switch set to either the “AUTO” or “HEAT” settings, the blower
is energized whenever a cooling or heating operation is
requested. The blower is energized after any specified delay
associated with the operation.
When energized, the indoor blower has a minimum run time of
30 seconds. Additionally, the indoor blower has a delay of 10
seconds between operations.
When the room t-stat calls for cooling, the low-voltage control
circuit from “R” to “Y1”and “G” is completed. The compressor
and fan motor are energized. After completing the specified
fan on delay for cooling, the micro processor control will
energize the blower motor.