Middleby Marshall PS570, PS360, PS200, PS555, PS220 Element bank removed spacer bracket visible, 143

4.Heater specifications

•PS310/360-series electric ovens use 18 heating elements in 3 banks (6 elements per bank).

•208V elements are used for ovens with a 208V supply.

•240 volt elements are used for ovens with a 220, 230 or 240V supply. 240V elements are also used on ovens with a 416V or 480V supply (connected in se- ries).

•380V elements are used for ovens with a 380V supply.

•All heaters are connected in Delta.

•Each element is stainless-clad and has a 4-7/8”/ 124mm cold (unheated) end next to the connect- ing leg.

•Individual element electrical data

Volts	Watts	Ohms	Connection
208V	1350W	32W	Parallel
220V	1134W	42.7W	Parallel
230V	1239W	42.7W	Parallel
240V	1350W	42.7W	Parallel
380V	1350W	107W	Parallel
416V	1013W	42.7W	Series
480V	1350W	42.7W	Series

5.Checking the Heating Elements

The most common problems encountered with electric heaters are:

•Open or bad connections.

•Open, shorted or grounded heating elements.

To troubleshoot the heating elements, disconnect all leads from ALL of the elements in the bank. Then, check each element with a digital multimeter set to

SECTION 3 - SERVICING COMPONENTS

Ohms (W). Correct ratings are shown in the table in the preceding section. Zero reading on the ohm scale indicates an open or shorted element.

It is also possible to check for an open element using an ampmeter. Any current through the element indi- cates that the element is not open.

6.Changing Heating Elements

NOTE: Wires going from the mercury contactors to the heating elements are rated at #12 gauge TAGT, 482°F/250°C. DO NOT, under any circumstances, use a wire of lesser rating or quality.

NOTE: All lugs and connections are rated at 600°F/ 316°C. All heating elements are double-nutted. The rear of each heating element is held to other elements by a spacer bracket. The only way the element can be changed is by removing the entire bank from the oven. To remove the element bank:

1.Remove the 4 bolts holding the bank of element to the oven. See Figure 80.

2.Remove the 9 electrical leads going to the element bank. See Figure 81.

3.Gently work the bank of elements out of the oven. Be careful not to pinch the wires between the frame of the oven and the side plate of the heating ele- ments. See Figure 82.

4.Remove the bank of elements and place them on the floor. The entire bank may now be serviced.

5.Remove the element jumper wires and element cover if individual elements need replacement.

NOTE: The spacer brackets MUST be reinstalled be- fore assembling the element bank back into the oven. These brackets keep the elements from touching each other during use. See Figure 82.

Figure 82

Element bank removed - spacer bracket visible

Spacer brackets

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