Testing; Testing Gate Interlocks; Testing Three-Wire Circuit Components On Each Interlocked Machine - Milnor MWF C Series Safety Manual

three-wire circuit a circuit that provides control power for all machine functions. Any of sev-
eral safety devices in the three-wire circuit will open the circuit and stop machine operation if
a malfunction is detected. Once open, the three-wire circuit can only be closed by manual in-
tervention and then only if the condition that opened the circuit is rectified.
W6SYSSG depicts schematically, various circuit segments the technician may encounter, depend-
ing on the type and age of the machine. Only one depiction will match a given machine. It may
be helpful to refer to the electrical schematics for your machine; however, you should be able to
identify the pertinent electrical components by referring to the tags inside the electric box doors
on your machine. You will use one of two wiring methods depending on which circuit segment
on W6SYSSG corresponds to your machine:
1. Jumpered terminals—Remove the jumper and connect the two incoming conductors to the
terminals (pins) where the jumpers were removed. A tag was tied to the jumper at the factory
to identify this as the gate interlock switch connection point.
2. Circuitry that must be split—Locate convenient connection points (e.g., a pin on a switch)
at which to split the circuit and connect the incoming conductors. You may need to splice
wires to complete the connection.
1.3.3

Testing

Once wiring is completed, it is vital to test the system to ensure that:
1. all gate interlocks function properly, and
2. all components that were part of the machine's three-wire circuit before the gate interlocks
were added continue to function properly. The objective is to ensure that the added wiring did
not inadvertently bypass existing components.
1.3.3.1

Testing Gate Interlocks

1. Close all gates.
2. Restore power to all interlocked machines.
3. For each gate:
a. Start all interlocked machines (
manual).
b. Open the gate and verify that all interlocked machines shut down (as indicated by their in-
dividual operator alarms).
c. Close the gate so the next gate can be tested.
1.3.3.2 Testing Three-wire Circuit Components on Each Interlocked
Machine
Typically, these include the components listed in
Pellerin Milnor Corporation
BNSUUI02.C04 0000230273 A.4 D.2 A.3 1/2/20 2:04 PM Released
BNSUUI02.C05 0000230272 A.4 D.2 A.3 1/2/20 2:04 PM Released
) and place in Manual mode (all machines idling in
BNSUUI02.C06 0000230271 A.4 D.2 A.3 1/2/20 2:04 PM Released
Table 1 .
For Owner/Management
11