Carrier 30HL - Electrical Box, Control Section; Unbalanced 3-Phase Supply Voltage; Electrical Box, Power Section

Refer to Tables 4 and 5 for electrical data on indi¬
vidual compressors and complete units. Compressor
usage is given in Tables 2 and 5.
ELECTRICAL BOX, CONTROL SECTION
Inside this section are relays, high- and low-
pressure cutouts, low water-temperature cutout,
timer, terminal strips and a 3-step temperature
controller. On the outside (control panel) are con¬
trol circuit ON-OFF switch, partial load switch
(DLS), compressor run light, safety trip lights and
control circuit fuse. The control panel is hinged to
provide easy access to the controls inside.
^ Table 4 — Unit Voltage and Model Number*
VOLTS 1
... 1
1 UN1T30HK,HL
015,020,025,030
208/230 j
5--
460
6--
_ 575 1
1 1--
*Complete number has 10 digits.
Example; 30HK020530.
UNBALANCED 3-PHASE SUPPLY VOLTAGE
Never operate a motor where a phase imbalance
in supply voltage is greater than 2%. Use the follow¬
ing formula to determine the % voltage imbalance:
% Voltage Imbalance =
average voltage
Example: Supply voltage is 240-3-60.
AB = 243 volts
BC = 236 volts
AC == 238 volts
Average Voltage =
243 + 236 + 238
3
= —— - 239 volts
Determine maximum deviation from average
voltage:
(AB) 243 - 239 = 4 volts
(BC) 239 - 236 = 3 volts
(AC) 239 - 238 = 1 volt
Maximum deviation is 4 volts.
Determine % voltage imbalance:
4
% Voltage Imbalance - 100 “ 1T%
This amount of phase imbalance is satisfactory
as it is below the maximum allowable 2%.
IMPGR PAN r: It the supply voltage phase im¬
balance is more than 2%^ contact your local
electric utility company immediately.
tQUIP GND
GND-^
TERMINAL
BLOCK
6-POLE
COMPRESSOR
CIRCUIT BREAKER
(LD-
IL2)-
FIELD CONTROL
POWER WIRING
TB2
--T^TBZ
Control circuit power is from separate source, incoming wires are
connected directly to terminals j 1 j and [ 2 | on TB2
EQUfPGND — Equipment Ground
Fig. 3 — Wiring Schematic — Unit and
Control Power Supply
ELECTRICAL BOX, POWER SECTION
The main electrical power supply is brought in
thru the top of the electrical box, on the left-hand
side (see Fig. i). The hole accommodates up to a
3-in. conduit. Pressure-lug connections on terminal
block are suitable for copper, copper-clad alumi¬
num or aluminum wire, unless otherwise noted on a
label near the terminal block.
The power section contains: main power terminal
block, compressor circuit breaker with calibrated
magnetic trip (for compressor motor overload and
locked rotor protection), and compressor motor
contactors. The panel over this section is secured
with screws as a safety measure against casual entry
for purposes other than service.
5
1090