Middleby Marshall PS740 Series Electric Ovens 60254 - Manual (Page 21)

17 P/N 60254 September 28, 2012
III. ELECTRICAL CONNECTION INFORMATION
FOR PS740E-SERIES OVENS.
WARNING
Authorized supplier personnel normally
accomplish the connections for the ventilation
system, electric supply, as arranged by the
customer. Following these connections, the
factory-authorized installer can perform the
initial startup of the oven.
Check the oven data plate (Figure 2-17) before making any
electric supply connections. Electric supply connections must
agree with data on the oven data plate.
NOTE: The electric supply installation must satisfy the require-
ments of the appropriate statutory authority, such as the National
Electrical Code (NEC), ANSI/NFPA70, (U.S.A.); the Canadian
Electrical Code, CSA C22.2; the Australian Code AG601; or
other applicable regulations.
A fused disconnect switch or a main circuit breaker (customer
furnished) MUST be installed in the electric supply line for
each oven; it is recommended that this switch/ circuit breaker
have lockout/tagout capability. The electric supply connection
must meet all national and local electrical code requirements.
Copper is the recommended material for the electrical supply
conductors.
Figure 2-17. Typical Electric Oven Data Plate
IV. ELECTRIC SUPPLY FOR ELECTRICALLY
HEATED OVENS
Power requirements for electrically heated ovens are usually
208 - 240VAC, 3-phase, 4-wire (3 ‘hot’, 1 ground), although
ovens built for export can have power requirements of 380VAC
and 480VAC. (These ovens have a 5-wire system.) A 2″ (51mm)
diameter cutout/hole in the back of the machinery compartment
provides access for the electrical supply connections. Using
flexible cable(s) for the electrical power supply conductors
requires a 2″ (51mm) strain-relief fitting (not furnished) to en-
able safe access to the terminal block from which oven power
is distributed.
The supply conductors must be of the size and material (cop-
per) recommended to provide the current required; (refer to the
data plate for the ampere specifications). The electric current
rating for each conductor supplying a PS740E-Series Oven
must comply to local and national codes.
Typical specifications for each PS740E-Series Oven
are 208V or 240V, 3-phase, 4-wire, 60-ampere, 34.4kW. A
PS740E-Series Double Oven (Figure 1-2) installation would
require two 60-ampere service connections, one for each
oven; the 34.4kW power consumption also doubles for such
an installation to 68.8kW.
The 208V or 240VAC electrically heated oven uses two legs
of the supplied power to provide 208V or 240VAC power for
the oven control circuitry.
Electrical Junction Box
(One per oven cavity)
Figure 2-18. Utility Connection Locations for Elec-
tric Ovens