14
M
INI
-S
PACE
EC I
NSTALLATION
, O
PERATION
AND
M
AINTENANCE
M
ANUAL
CAUTION
Verify facility power to the unit matches the voltage,
phase and frequency specified on the system
nameplate. Supply voltage measured at the unit
must be within ±10% of the voltage specifi ed on
the system nameplate except for 208/230V single-
phase units, which have a different tolerance listed in
the sections to follow.
A main distribution panel must be provided with a manual
fused disconnect switch or HACR-type circuit breaker
per local and national electrical codes for service to the
equipment. Do not mount a customer-supplied manual fused
disconnect switch or HACR-type circuit breaker to the surface
of the A/C unit.
The unit is provided with a main power pilot hole and a
control wiring pilot hole for connection of field-wiring
conduits. Typically, these pilot holes are located on the side
of the Mini-Space
EC cabinet. A label stating “MAIN POWER
INPUT” is placed in close proximity.
Terminate the main power wires at the line side of the main
power disconnect switch located within the electric box (see
Figure 9). A separate equipment ground lug is provided in the
electric box for terminating the earth ground wire.
The size of the electric box and location of its components
vary according to the Mini-Space EC model. Electric box
components are labeled with reference designators which are
identifi ed by name on the unit electrical drawing contained in
the data package accompanying the unit.
CAUTION
Prior to unit operation, an adequate unit-to-earth
ground must be connected.
2.8.1.1
Single-Phase Units 208/230V
The supply voltage for units that are designed for 208V
operation must have a tolerance within -5% and +10%. If the
measured supply voltage is 230V, the unit can operate with a
tolerance of ±5% if the following change is made. The control
transformers within the system must have the primary wire
connected to its respective 240V
tap instead of the 208V tap.
2.8.1.2 Three-Phase
Units
Three-phase units are designed to have the L1, L2 and
L3 supply wires connected to corresponding L1, L2 and
L3 line terminals of the non-fused main power disconnect
switch. The unit will operate correctly if the supply wires are
connected in this manner. A ground lug is provided in each
unit near the non-fused main power disconnect switch. Prior
to unit operation an adequate unit-to-earth ground must be
connected to the unit.
CAUTION
Improper wire connections will result in reverse
rotation of the compressor (if applicable) and may
eventually result in damage to the compressor in DX-
based systems. To correct this problem, exchange
any two of the incoming main power wires at the main
power disconnect switch. Do not rewire the unit’s
individual components.
2.8.2 Controls
The
E²
is the standard controller for Mini-Space EC systems.
If the graphic terminal is mounted on the unit (standard),
no utility connection is required. As an option, the graphic
terminal may be factory supplied for remote mounting. A
cable harness is typically provided for the interconnect wiring.
Refer to the
STULZ E
2
Series Microprocessor Controller
Operators Manual
and the electrical drawing supplied with
your unit for details on connecting the graphic terminal.
2.8.3 Optional
Equipment
NOTE
All wiring must be provided in accordance with local
and national electrical codes.
2.8.3.1 Condensate
Pump
Systems supplied with a fi eld-installed condensate pump
require power and control wiring to be connected to the
unit. After installing the condensate pump, the installer must
connect two power conductors from the condensate pump
main power terminals to the air conditioning unit. A ground
wire must be connected to the unit ground stud located in
the unit electric box.
Two control conductors must be wired to the control terminal
board located in the unit electric box. The control wires from
the terminal board in the electric box should be run through
the overfl ow switch in the condensate pump housing. The
condensate pump is equipped with pigtail leads for splice-
type wire connections with twist-on connectors (wire caps).
Refer to the electrical schematic supplied with your unit for
proper wire terminations.
2.8.3.2
Remote
Temperature/Humidity
Sensor
Each remote temperature/humidity sensor requires a
three-conductor shielded cable with the shield being
terminated at the unit electric box. Both the electric box and
the sensor include a terminal strip with box-type lugs for wire
connections. Refer to the electrical drawing supplied with your
unit for proper wire terminations.
