Mammoth V-Cube Slim Split F-Series Sizes 830 and 840 - Manual (Page 16)

Mammoth V-Cube Slim Split IOM, MAMM-VCS-IOM-3FA (September 2013) 16
Blowers and Fans
Switch the motor protectors for the supply air fans to the
On position (see page 6 for motor protector locations).
Turn the system switch to the On position, then carry out
the following checks:
•
Verify that the unit controller is calling for the unit to
operate. Consult the controls documentation provided
with your unit to trouble shoot any problems.
• Measure the amp draw of all blowers and fan motors
and record them on the startup report form. Verify
that they do not exceed the FLA listed on the motor
nameplate. Amp draw can be checked using an amp
draw meter clamped around the motor wires leading
into the motor protectors for each motor. See Figure
15.
Figure 15: Amp Draw Check
• Verify that the parameter settings are correct on the
supply and return/exhaust fan VFDs, as applicable.
Refer to the parameter settings that are detailed on
the wiring diagrams provided with your Mammoth
unit. Refer to the instruction manual for the VFD for
information on how to navigate through the parameter
menus.
DX Cooling Startup
A reasonable cooling load must be available to perform
a proper cooling startup. With a cooling load available,
carry out the following procedure on each circuit:
1. Install refrigeration gauges on the compressor circuit
to be started.
2. Turn the unit system switch to the on position.
3. Verify that the liquid sub-cooling is between 10 and
12 degrees F (8 to 10 degrees F for shell and tube or
flat plate condensers).
4. Verify that the super heat is within 12 to 18 degrees F
at the compressor.
Repeat each step above for all additional compressor cir-
cuits to be started.
Geothermal Units Only
For geothermal units only, verify that the low-pressure
switches installed on the suction line of each compores-
sor are all labeled “40 to 50 PSI.” This is accomplished as
follows:
1. Remove the front cover from the main chassis on
both halves of the V-Cube Slim Split unit.
2. The low pressure switches are inserted into the com-
pressor suction piping about halfway up the overall
height of each compressor. See Figure 16
3. Do not attempt to turn or rotate the switch.
4. View the label on each of the switches. It should read
“40 to 50 PSI.” If it does not, contact your Mammoth
representative to replace the switch.
Note: Due to tight quarters, an inspection mirror or smart
phone photo may be necessary to view the pressure
range label on the switch.
Figure 16: Pressure Switches
Pressure switches (one per compressor)