Trane Voyager RT-SVX17C-EN, Установка, эксплуатация и обслуживание

Страница: 38 / 80

38
Unit Start-Up (Continued)
Voltage Imbalance
Excessive voltage imbalance between phases in a three
phase system will cause motors to overheat and eventually
fail. The maximum allowable voltage imbalance is 2%. Mea-
sure and record the voltage between phases 1, 2, and 3 and
calculate the amount of imbalance as follows:
% Voltage Imbalance = (AV - VD) X 100 where;
AV
AV (Average Voltage) = Volt 1 + Volt 2 + Volt 3
3
Volt 1, Volt 2, Volt 3 = Line Voltage Readings
VD = Line Voltage reading that deviates the farthest
from the average voltage.
Example:
If the voltage readings of the supply power
measured 221, 230, and 227, the average volts
would be:
221 + 230 + 227 = 226 Avg.
3
VD (reading farthest from average) = 221
The percentage of Imbalance equals:
226 - 221 X 100 = 2.2%
226
The 2.2% imbalance in this example exceeds the maximum
allowable imbalance of 2.0%. This much imbalance between
phases can equal as much as a 20% current imbalance with
a resulting increase in motor winding temperatures that will
decrease motor life.
If the voltage imbalance at the job site is over 2%, notify the
proper agencies to correct the voltage problem to within
2.0% before operating this equipment.
Starting the Unit
Before closing the main power disconnect switch, insure that
the "System" selection switch is in the "Off" position and the
"Fan" selection switch for Constant Volume units is in the
"Auto" position.
Close the main power disconnect switch and the unit
mounted disconnect switch, if applicable.
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote discon-
nects before servicing. Follow proper lockout/tagout
procedures to ensure the power can not be inadvertently
energized. Failure to disconnect power before servicing
could result in death or serious injury.
HIGH VOLTAGE IS PRESENT AT TERMINAL BLOCK
HTB1 OR UNIT DISCONNECT SWITCH.
Upon power initialization, the RTRM performs self-diagnos-
tic checks to insure that all internal controls are functional. It
also checks the configuration parameters against the compo-
nents connected to the system. The LED located on the
RTRM module is turned "On" within one second of power-
up if internal operation is okay. The economizer dampers
are driven open for 5 seconds then fully closed (if appli-
cable).
When an economizer is installed ....DO NOT ENTER the
TEST mode until all calibration start-up functions have been
completed. Otherwise, the economizer actuator and power
exhaust output may not function properly during any of the
test mode steps. Allow 2 minutes after unit power up to com-
plete economizer calibration before entering the test mode
function.
Use the following "Test" procedure to bypass some time de-
lays and to start the unit at the control panel. Each step of
unit operation can be activated individually by temporarily
shorting across the "Test" terminals for two to three seconds.
The LED located on the RTRM module will blink when the
test mode has been initiated. The unit can be left in any
"Test" step for up to one hour before it will automatically ter-
minate, or it can be terminated by opening the main power
disconnect switch. Once the test mode has been terminated,
the LED will glow continuously and the unit will revert to the
"System" control, i.e. zone temperature for constant volume
units or discharge air temperature for variable air volume
units.
Test Modes
There are three methods in which the "Test" mode can be
cycled at LTB1-Test 1 and LTB1-Test 2.
1. Step Test Mode - This method initiates the different com-
ponents of the unit, one at a time, by temporarily shorting
across the two test terminals for two to three seconds.
For the initial start-up of either a Constant Volume or Vari-
able Air Volume unit, this method allows the technician to
cycle a component "on" and have up to one hour to complete
the check.
2. Resistance Test Mode - This method can be used for start-
up providing a decade box for variable resistance out-
puts is available. This method initiates the different com-
ponents of the unit, one at a time, when a specific resis-
tance value is placed across the two test terminals. The
unit will remain in the specific test mode for approxi-
mately one hour even though the resistance is left on the
test terminals.
3. Auto Test Mode - This method is not recommended for
start-up due to the short timing between individual com-
ponent steps. This method initiates the different compo-
nents of the unit, one at a time, when a jumper is in-
stalled across the test terminals. The unit will start the first
test step and change to the next step every 30 seconds.
At the end of the test mode, control of the unit will auto-
matically revert to the applied "System" control method.
For Constant Volume or Variable Air Volume test steps, test
modes, and step resistance values to cycle the various com-
ponents, refer to Figure 13.