Engineered air DG SERIES, Инструкция по установке, эксплуатации и обслуживанию

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DJ & DG MANUAL
18 of 34 May 12 R2
9.
Check the amperage draw of each motor and compressor. Refer to unit or motor rating plate for full
load amps. At the unit, check and record the voltage while it is running. For 3 phase power the
phase to phase voltage imbalance should be less than 2%. A 2% voltage imbalance can cause up
to a 10% current imbalance that will overheat motor windings.
To calculate voltage imbalance (NEMA method) refer to the following example:
Phase to phase voltage readings: 235V 236V 230V
The average Voltage between legs is 233.7V (235+236+230)/3
Highest voltage deviation from average is: 233.7V – 230V = 3.7V
Voltage imbalance percentage = Highest deviation divided by average X 100
3.7 / 233.7 x 100 = 1.6% This imbalance is less than 2% and therefore is OK
If voltage imbalance is greater than two percent (2%), turn off main disconnect and contact
the installing electrical contractor to have the voltage condition corrected.
10.
Purge all the air from the gas (oil) lines. Refer to the Canadian Natural Gas and Propane
Installation Code, C.S.A. Standard B149.1 or the National Fuel Gas Code ANSI/Z223.1/NFPA 54
for proper method. Check all connections for leaks and correct. Ensure that the inlet pressure
agrees with the approval label.
11.
Enable heating and/or cooling; refer to unit function for correct sequence and operation.
12.
Confirm field wiring voltage drop is less than 10% when equipment is operating.
13.
For the unit to operate properly a system air balance must be performed to ensure correct air flow.
Failure to do so can damage the equipment and/or building and can be a cause of poor indoor air
quality.
14.
Damper sections:
a. Flat mixing dampers:
Both the fresh air and return air dampers are fully open when the dampers are at a 45° angle when
fully stroked. This provides optimum mixing of the air streams for this damper arrangement.
b. Angle mixing damper:
Angle mixing section dampers open to an angle of 90° when fully stroked. This provides optimum
mixing of the air streams for this damper arrangement.
15.
Some units are equipped with an adjustable coil air bypass. This must be field adjusted during the
system air balance to ensure proper air flow across the coil. Adjust the bypass to achieve coil
pressure drop as stated on the submittal and/or the unit function sheet.
16.
Check setting of fan limit control(s). Adjust high limit to value indicated below unless wiring diagram
shows a different value.
High Limit
180°F (82°C)
Fan Switch ON 125°F (52°C)
OFF 90°F (32°C)
17.
Set all controls to the settings indicated on the wiring diagram.
18.
Re-install all access panels.