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SECTION 2
INSTALLATION
15
V. GAS SUPPLY
CAUTION
DURING PRESSURE TESTING NOTE THE FOLLOWING:
1. The oven and its individual shutoff valve must be discon-
nected from the gas supply piping system during any
pressure testing of that system at test pressure in excess
of 1/2 psi (3.45 kPa).
2. The oven must be isolated from the gas supply piping
system by closing its individual manual shutoff valve dur-
ing any pressure testing of the gas supply piping system
at test pressure equal to or less than 1/2 psi (3.45 kPa).
3. If incoming pressure is over 14
″″
″″
″ W.C. (35mbar), a
separate regulator MUST be installed in the line BEFORE
the individual shutoff valve for the oven.
WARNING:
To prevent damage to the control valve regu-
lator during initial turn- on of gas, it is very important to
open the manual shutoff valve
very slowly.
After the initial gas turn-on, the manual shutoff valve must
remain open except during pressure testing as outlined in the
above steps or when necessary during service maintenance.
A. Gas Utility Rough-In Recommendations
The following gas system specifications are STRONGLY
RECOMMENDED. Deviating from these recommendations
may affect the baking performance of the oven.
Gas Meter -
650 cfh (307l/min) meter
Gas Line
• DEDICATED LINE from the gas meter to the oven
• 1-1/2" (50.8mm) pipe for natural gas
• 1-1/2″ (38.1mm) pipe for propane
• Maximum length: 200' (61m). Each 90° elbow equals 7'
(2.13m) of pipe.
B. Gas Conversion
Ovens are shipped from the factory configured for use with
natural gas. If permitted by local, national and international
codes, the oven may be converted to propane gas operation
using a Gas Conversion Kit that is supplied with the oven. Gas
orifice sizes supplied with the Kit match those shown in the
Tables on page 2 in the Description section of this Manual.
Where permitted by local and national codes, it is possible to
convert ovens from natural to propane gas, or from propane to
natural gas, after the oven has been installed. Gas Conversion
Kits are available from Middleby Marshall for this purpose.
C. Connection
WARNING
Some procedures in this section may require conversions,
readjustments, or service on the oven's gas system. Before
performing these procedures, check that the main
gas supply valve and the circuit breaker/fused discon-
nect are in the OFF (“O”) position. After completing
these procedures, perform a gas leak test before operating
the oven.
CAUTION
The terms of the oven's warranty require all start-ups, conver-
sions and service work to be performed by a Middleby Marshall
Authorized Service Agent. The installation, start-up and changes
required when changing from one gas type to another can be
performed ONLY by a certified professional.
NOTE:
Certain safety code requirements exist for the installation
of gas ovens; refer to the beginning of Section 2 for a list of the
installation standards. In addition:
• In the USA,
the installation must conform with local codes,
or in the absence of local codes, with the National Fuel Gas
Code, ANSI Z223.1.
• In Canada,
the installation must conform with local codes,
or in the absence of local codes, with the Natural Gas
Installation Code, CAN/CGA-B 149.1, or the Propane
Installation Code, CAN/CGA-B 149.2, as applicable.
• In Australia,
the installation must conform with AGA Codes
AG311 and AG601, and with any requirements of the
appropriate statutory authority.
• In CE countries,
the gas supply connection should be
according to EN-203 (gas appliance directive) and to
applicable ISO 228-1 or ISO 7-1 recommendations. All
aspects of the gas supply connection must comply with
current IEC/CEE requirements and with all applicable
local, national, and international codes.
• For all ovens equipped with casters,
the gas line connection
shall be made with:
- A connector that complies with the Standard for
Connectors for Movable Gas Appliances, ANSI Z21.69
(in USA), or Connectors for Movable Gas Appliances,
CAN/CGA-6.16 (in Canada).
Check the oven’s gas supply requirements to determine the
type of gas to be used with the oven. If the gas type required does
NOT match the local supply:
• For North American installations,
a conversion kit is
supplied with the oven to allow operation using propane
gas. Refer to Part B,
Gas Conversion, in this section.
• For CE ovens, directions for converting the oven for use with
other gases are described in Part D.1, Preparation for Use
with Various Gases, in this section.
If the installation will use the supplied gas hose, be sure that
the 1/2″ to 3/4″ gas line fitting is attached. Refer to the
instructions in the gas hose package. One gas line connection
method is shown in Figure 2-12; however, compliance with the
applicable standards and regulations is mandatory.
Inlet and regulated gas pressures can be measured using a “U” tube
manometer at the tap locations shown in Figures 2-12 and 2-13.
Figure 2-12 - Flexible Gas Hose Installation
To Gas
Supply
Pipe
90°
Elbow
Quick-
disconnect
device
Flexible
Gas Hose
Full-Flow
Gas
Shutoff
Valve
3/4" gas
pipe nipple
3/4"-1/2"
gas pipe
reducer
Individual gas
connection for
each oven
cavity
1/2" gas
pipe nipple
1/2" gas line
tee with
pressure tap