10
Locate unit rating plate which contains proper installation
information. Check rating plate to be sure unit matches job
specifications.
C. System Type
The type of system must be selected.
1. AC—air conditioner (approx. 350 CFM/ton)
2. HP--COMFORT—provides lower airflow than air condi-
tioner selection (approximately 315 CFM/ton) in heating
mode. In cooling mode supplies 350 CFM/ton.
3. HP--EFF—provides same airflow for heat pump heating
and cooling modes (approximately 350 CFM/ton).
The factory setting is AC. (See Fig. 7.)
D. AC/HP CFM Adjust
Select low, nominal, or high airflow. The factory selection is NOM.
The adjust selections HI/LO will regulate airflow supplied for
cooling and heat pump heating modes only, +15 percent and --10
percent respectively. The adjust selection options are provided to
adjust airflow supplied to meet individual installation needs for
such things as noise, comfort, and humidity removal. (See Fig. 7.)
E. ON/OFF Delay
NOTE: ON/OFF Delay is active only in cooling and heat pump
only heating modes. In auxiliary heat mode or emergency heat
mode, the ON delay is 0 seconds and the OFF delay is fixed and
cannot be overridden.
Select desired time delay profile. Four motor--operation delay
profiles are provided to customize and enhance system operation.
(See Fig. 7.) The selection options are:
1. The standard 90--seconds off delay (factory setting 0/90).
2. No delay option used for servicing unit or when a thermo-
stat is utilized to perform delay functions (0/0).
3. A 30--seconds on/90--seconds off delay profile used when it
is desirable to allow system coils time to heat up/cool down
prior to airflow. This profile will minimize cold blow in
heat pump operation and could enhance system efficiency
(30/90).
4. ENH, enhanced selection provides a 30--seconds
on/150--seconds at 70 percent airflow and no off delay.
F. Continuous Fan
Select desired continuous--fan profile LO, MED, or HI. Airflow are
provided to customize and enhance the continuous fan functions.
(See Fig. 7.) The possible selections are:
1. LO—provides 50 percent of Y/Y2 Cool airflow.
2. MED—provides 65 percent of Y/Y2 Cool airflow (71 per-
cent on 006 model).
3. HI—provides 100 percent of Y/Y2 Cool airflow.
The factory setting is LO.
NOTE: If applied to two--speed unit, do not select continuous fan
as HI since low speed cooling will also run at HIGH airflow and
insufficient dehumidification may result.
G. Easy Select Board Jumpers
J1 -- This jumper must be pulled to activate dehumidification
mode. The jumper connects R to DH. With the jumper in, the DH
terminal is always energized. With the jumper pulled, the DH
terminal is de--energized. A control such as the Thermidistat must
be used to supply the 24--V signal when there is no call for
dehumidification, and turn off the 24--V when there is a call for
dehumidfication.
J2 -- This jumper activates heat staging. The jumper connects the
W1 and W2 terminals together. If either is energized, W2 airflow is
delivered. With the jumper pulled, there are separate airflows for
W1 and W2.
H. Airflow Delivery
These units deliver airflow depending on the system size selections
and operating mode. The thermostat energizes a combination of
terminals on the Easy Select Board which tells the motor what
CFM to deliver. The following are typical operating modes and the
terminals that should be energized on the Easy Select Board.
NOTE: The DH terminal on the Easy Select Board is for
dehumidification. It is de--energized on a call for dehumidification.
I. Variable Speed Motor Logic Sequence:
The ECM motors in these fan coils are programmed to deliver a
variety of airflows. The motor goes through:
COOLING
The nominal cooling airflow for these fan coils is 350 CFM per
ton. Selecting the HI adjust tap increases the airflow to 400 CFM
per ton. The LO tap decreases airflow to 315 CFM per ton. The
low adjustment is only active during normal cooling mode.
Removing the signal from the DH terminal reduces the airflow to
80 percent of cooling airflow. Removing the G signal for
Superdehumidify reduces the airflow to 50 percent of cooling.
HEATING
The base heat pump only heating airflow is determined by the
SYSTEM TYPE selection on the Easy Select Board. If
HP--EFFICIENCY is selected, the airflow is the same as Cooling.
IF HP--COMFORT is selected, the airflow is 315 CFM per ton.
The airflow will adjust up if necessary when auxiliary heating is
required. When both the Y/Y2 and W1 or W2 terminals are
energized, the motor will run the higher of the heat pump or
electric heat airflows. During Super Comfort Heat mode, the
indoor control removes the G signal from the board. This slows the
motor to 75 percent of heat pump airflow. If the CFM adjust is set
to LO, it will deliver 67.5 percent of heat pump airflow during
Super Comfort Heat mode.
TROUBLESHOOTING
A. Troubleshooting Easy Select Board (FV4)
If Traces Are Overheated on Back of PCB:
Usually whenever there is a trace broken on PCB, it means either
there has been a high--voltage short or high voltage has been
applied to low--voltage circuit. This can be prevented by making
sure PCB is wired correctly before fan coil has power applied to it.
If PCB Fuse Keeps Blowing:
When low--voltage fuse blows, it means transformer would have
blown if fuse had not been in circuit to protect it. The fuse usually
blows when there is a high current drawn on transformer, high
voltage applied to low--voltage circuit, or a direct secondary short.
When there is a high current drawn on transformer, it is most likely
because transformer has been shorted or system is trying to draw
more Vac than transformer rating allows. When fuse blows because
of high voltage, the system has mixed high and low--voltage
signals.
1. Check transformer and thermostat wiring. (See Fig. 7.) Be
sure transformer is not shorting out because thermostat
wires are miswired.
2. Check wiring of relays. (See Fig. 7.) Be sure low--voltage
and high--voltage wiring are connected to proper sequen-
cers.
3. Check VA draw on transformer. If VA draw is more than
VA rating of transformer, fuse will blow. If this is the case,
replace transformer with one that has a higher VA rating.
B. Troubleshooting Common Problems
Airflow Too Low:
Y1 instead of Y/Y2 on single--speed air conditioner or heat pump
application. Y1 input is only for two--speed applications. Using
this terminal will deliver about 60 percent of full cooling airflow.
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