EngA RUVG SERIES, Installation, Operation And Maintenance Manual

Page: 23 / 35

A
RUVG MANUAL
23 of 35 June 14
BEFORE START ‐ UP
Remove tie ‐ down bolts, straps and blocks on fan and compressor vibration isolators, tilt equipped heat
pipes and enthalpy/desiccant wheels if supplied.
Perform a Safety Shutoff Valve Leak Test as described in this manual.
START ‐ UP CHECK LIST
Warning: This unit is connected to high voltages. Electrical shock or death could occur if
instructions are not followed. This equipment contains moving parts that can start
unexpectedly. Injury or death could occur if instructions are not followed. All work
should be performed by a qualified technician. Always disconnect and lock out power
before servicing. DO NOT bypass any interlock or safety switches under any
circumstances.
The start ‐ up and operation must be in accordance with safe practices. Start ‐ up must be performed by
qualified personnel. Complete attached start ‐ up record.
1. Set all associated electrical switches, controls, thermostats and main disconnect switch to “OFF”
position.
2. Close all manual valves and field piping valves.
3. Confirm that all shipping materials have been removed. See any supplemental instructions shipped
with the unit to help identify possible locations.
4. Check all bearings, drive and fan set screws for tightness.
5. Turn disconnect switch ON (control switch is still off) and check the supply voltage. Voltage must be
within 10% of rating plate. If not, contact the installing electrical contractor and have the voltage
condition corrected before continuing start ‐ up.
6. Check all fan motors for correct rotation. If incorrect, reverse rotation on incoming power only.
7. Set thermostat or controller to the “OFF” position and turn unit control switch “ON”.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.