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SERVICE
TEST
HMZR
CALIBRATE)
On Humidi-MiZer configured units, this item allows the user to
calibrate the valve that controls discharge gas bypass around the
Circuit B condenser. Switching B.CAL to ON will instruct the unit
software to over-drive the valve in the closing direction. This is to
assure that the valve is completely shut and to establish the "zero"
open position. The controller then keeps track of the valve's posi-
tion for normal operation. During this calibration phase, a light
ratcheting sound may be heard and will serve as proof of valve op-
eration and closure. Note that the calibration feature in Service
Test is only provided as an additional troubleshooting tool. The
valves automatically go through the calibration process anytime
the unit is powered down, unit power is cycled, or communication
is lost between the EXV board and the valve. There should be no
need to manually calibrate the valves under normal circumstances.
Cooling
The cooling sub-menu offers many different service tests.
•
Service Test
Cool
E.POS (Econo Damper Command
Pos). It is possible to manually move the actuator during
the cooling test mode at all times, regardless if economizer
cooling is suitable or not.
•
Service Test
COOL
Upon entering the cooling sub-menu, the static pressure con-
trol item will default to the unit's static pressure set point.
Thereafter, as mechanical cooling commences and the fan
starts, the static pressure can be manually adjusted during the
cool mode without affecting the configured set point for nor-
mal runtime operation. By adjusting the static pressure set
point, the user can increase or decrease the supply airflow. Do
not use a static pressure that will exceed the system limits.
•
Service Test
COOL
this item is set to a non-zero value, the current assigned com-
pression stage for this unit will be selected and enacted.
Thereafter, the individual compressor will be "read-only" and
reflect the current staging state. In addition, this item will au-
tomatically clamp the cooling stages to its pre-configured
maximum.
•
Manual relay control of individual compressors. If the
cooling stage pattern request is set to zero, the user will
have the ability to manually control compressors. If the
user energizes mechanical cooling, the supply fan and the
outdoor fans will be started automatically. During mechan-
ical cooling, the unit will protect itself. Compressor diag-
nostics are active, monitoring for high discharge pressure,
low suction pressure, etc. The user can also turn the mini-
mum load valve on and off and set the digital scroll capac-
ity (on units equipped with this device).
•
Service Test
COOL
On Humidi-MiZer equipped units, this item allows the user to
switch the reheat valve from ON to OFF and vice versa.
When RHV is switched to the ON position, a three-way valve
will be energized, allowing refrigerant flow to enter the reheat
coil as if in a dehumidification mode or reheat mode. When
RHV is switched to the OFF position, the three-way valve
will be deenergized and the unit will revert back to normal
cooling. Note that this function only allows manipulation of
RHV if a compressor on Circuit B has already been turned
ON. To manually exercise this valve without an active
Circuit B compressor, see the section titled Service Test
HMZR
RHV. To view the actual valve position at any time,
use the Outputs menu (Outputs
B.CAL
(BYPASS
SP.SP (Static Pressure Set Point).
CL.ST (Requested Cool Stage). If
RHV (Humidi-MiZer 3-Way Valve).
COOL
RHV).
EXV
•
Service Test
Position). On Humidi-MiZer equipped units, this item al-
lows the user to exercise the valve that controls refrigerant
flow to the Circuit B condenser. To exercise the valve,
RHV must first be switched to ON (Service Test
COOL
RHV) and a Circuit B compressor must be com-
manded ON. The valve default position is 100% (com-
pletely open). The user will be able to adjust the valve
from 0 to 100% through this function. The only constraint
on the valve position is that the percentage sum of the by-
pass valve (Service Test
er valve must equal 100%. For example, if the condenser
modulating valve is only 80% open, then the gas bypass
modulating valve must remain at least 20% open. The ef-
fect of closing the condenser valve will be to increase the
supply air temperature (additional reheat capacity). To
view the actual valve position at any time, the user can use
the Outputs menu (Outputs
•
Service Test
sition). On Humidi-MiZer equipped units, this item allows
the user to exercise the valve that controls discharge gas
bypass around the Circuit B condenser. To exercise the
valve, RHV must first be switched to ON (Service Test
COOL
RHV) and a Circuit B compressor must be com-
manded ON. The valve default position is 0% (completely
closed). The user will be able to adjust the valve from 0 to
100% through this function. The only constraint on the
valve position is that the percentage sum of the bypass
valve and condenser valve (Service Test
C.EXV) must equal 100%. For example, if the condenser
modulating valve is only 80% open, then the gas bypass
modulating valve must remain at least 20% open. The ef-
fect of opening the bypass valve will be to increase the
supply air temperature (additional reheat capacity). To
view the actual valve position at any time, the user can use
the Outputs menu (Outputs
Heating
The Heat Test Mode sub-menu will offer automatic fan start-up if
the unit does not have gas fired heat. On gas heat units, IGC feed-
back from the gas control units will bring the fan on as required.
Within this sub-menu, control of the following is possible:
•
Service Test
When this item is non-zero, the currently configured heat
type will energize the corresponding heat relay pattern that
reflects the requested stage. In addition the upper limit will
be clamped to reflect the maximum configured number of
stages. When non-zero, the heat relays will be "read-only"
and reflect the currently selected pattern.
•
Service Test
H.I.R (Manual Heat Relay Control). If the "Heat Stage Re-
quest" item is set to zero, it will be possible to individually
control the heat relays, including the heat interlock relay.
•
Service Test
ty). If configured for modulating gas or SCR electric heat,
the user will be able to manually control the capacity of the
modulating heat section (0 to 100%). The requested heat
stage must be greater than or equal to 1 or heat relay 1
must be on before the control will accept a modulating
heat capacity request. If neither case is true, the control
will overwrite the modulating heat request back to 0%.
•
Service Test
tion). If configured for hydronic heat type, the user will be
able to manually control the positioning of the actuator
which controls hot water (0 to 100%).
41
COOL
C.EXV (HMV-1: Condenser EXV
COOL
B.EXV) and condens-
COOL
C.EXV).
COOL
B.EXV (HMV-2: Bypass EXV Po-
COOL
HEAT
HT.ST (Requested Heat Stage).
HEAT
HT.1-6, Service Test
HEAT
H1.CP (Modulating Heat Capaci-
HEAT
HTC.C (Ht Coil Command Posi-
COOL
B.EXV).
HEAT
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Table of Contents
Troubleshooting
