Middleby Marshall PS638 Series, Руководство владельца по эксплуатации и установке

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26
C. G
AS
O
VEN
I
NITIAL
I
GNITION
S
EQUENCE OF
O
PERATION
The PS638G performs the following
sequence of operation when first turned on:
A. Turns main blower on for 15 seconds. If
the oven uses a pressure switch, it
would check the opening/closing of the
pressure switch. If the oven uses a
rotation sensor, then it would check the
sensor signal to make sure fans are
running.
B. Turns main blower on at low speed and
the burners on at 100% full open valve
(the red energy indicator level bar will be
at the maximum height). The Blower &
Burner System will remain in this ignition
“lighting” position for 60 seconds.
C. The Igniter Lights the Burner Flame.
D. The burner modulation valve moves to
the low by-pass position for 80 seconds.
This is the flame sensor-rod cleaning
position = low blower rpm’s -and- low
flame(no red energy bar)
E. The Burner and Blower Systems will
ramp-up to full-power, full-
operation.(maximum red energy level
indicator bar height)

Lowering the oven temperature more
than 30
o
F will turn the burner off until the
actual oven temperature decreased to
this new temperature set point. The
burner will then relight without
performing the full ignition sequence of
operation cycle.

If the flame sense were lost, then the
oven would immediately attempt to
relight without any change of flame or
blower (i.e. immediate sparking
sequence, followed by the inter-purge
sequence of 15 seconds; three
spark/inter-purge cycles to re-light
before ignition lock-out).

If the oven is turned off and then turned
back on, then the full Ignition Sequence
of Operation will cycle accordingly.
D. E
NERGY
M
ANAGEMENT
I
NFORMATION
The PS638 reduces energy usage in two ways
over most competitive ovens:

Modulating Gas Control (Gas Energy
Management System)

Pulsing Solid State Relay (Electric Energy
Management System)

BAKING / IDLE Blower Speed (Energy
Saving Mode)
The modulating gas valve within the oven
controls pressure of the delivered gas to the
burners to increase or reduce the energy
input as needed to maintain temperature
instead of cycling a gas valve on and off. This
is a more efficient and accurate way of
controlling the temperature and eliminates the
losses associated with the ON/OFF
HIGH/LOW cycling control.
The PS638 like other Middleby WOW ovens
has an optional idle mode that places the
blowers at a reduced speed during non-
baking periods. Reducing the blower speed
reduces the volume of air movement requiring
heating and thus reduces energy usage
during these non-baking times. A photo eye
sensor at the entrance side of the baking
chamber detects when food is placed on the
belt and brings the oven up to the higher
(baking) blower speed, increasing the amount
of impingement convection air needed to cook
products faster. When the product passes the
photo eye, the controller begins a preset
timed period that insures the product will pass
fully through the oven before the oven returns
to the IDLE mode. With this energy
management scheme, the oven provides the
increased convection heat transfer needed for
fast baking, without the energy penalty during
non-baking times. This functionality is fully
automatic and requires no user interaction.