MPM Accuflex Printer Electrical problem

I had a similar problem once on an acculfex. The root cause was a short on the one the wire harnesses connected to the print head.

If I recall, most of the relays in an accuflex are actuated by the 24 volt bus, so if you have a short anywhere in that circuit your relays won't latch. Zeroing in on this is a pain in the butt. check your schematics, and unplug wire harnesses once at a time, and power cycle the machine, until the 24VS light stays lit. That should get you close to the issue.

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Sounds like a fuse, there are many on this system

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Jeff R,

The "24VS" stands for 24VDC Voltage Switched; meaning that it is supplied under machine control and other things have to happen in the machine before 24VS is applied, in this case to KP1 coil. KP1 coil/contact is in place as part of the power latch circuit for turning on the machine. I could go into a long explanation of the entire circuit, but let's just try and get your machine running if you haven't done so already. The most likely failure in your circuit is the "SR1" Banner Safety Relay," this is the module on DIN rail just in front of the larger KM1 & KM2 power contactors; it has black terminal caps and a red label. There are 3 LEDs on the top of the module. Under normal conditions the one that is a bit by itself indicates power to the module. If no light there is either no 24V (direct) from the power supply, or fuse 154FU is blown, or the Banner relay is faulty. If the light is lit check for 24V on the coil of the Banner (A1-A2) just to be sure. The other pair of LED's represent the Estop series wire loops (2 loops for safety) and if they are liy they indicate that both of the Estops are released. Two separate wire paths run from the Banner through the left Estop, then the Right Estop and back to the Banner. If either of the Estop push buttons is not released normally both LED's will be out. If only one LED is not lit, it could be that one of the Estop switches in broken, or maybe the contact assembly is loose on the back of one of the Estops from being stuck to hard, or a faulty Banner relay. If all the LED's are on then its probably a faulty Banner relay, but we still have a couple of things to do that might get you going. As I mentioned before the Banner is a safety relay, but it can be bypassed if it is truly bad. You need to connect two pairs of wires together. You can do this by removing the pairs of wires and wire nutting them together or by leaving the wires in place and add jumper wires from terminal to terminal. The wires that need to be paired at the Banner are 13-14 and 23-24 (see schematic sheet 13 if you have one). If the Banner is faulty, which is the root cause 95% of the time, then this will get you running, but proceed with caution as your Estops will no longer work. There is no more issue to be aware of that you should test, if you have troubleshot down to the Banner, and that is the Reset loop, terminals S33 and S34 on the Banner. From S33 a wire leaves the Banner and travels through the N/C normally closed contacts of KM1 and then KM2 contactor and back to S34 on the Banner. This is the reset loop for the Banner. When the machine energizes under normal conditions, KM1 & KM2 will close to source power to the machine and both N/C contacts will open. When the machine is powered off KM1 & KM2 deenergize and the N/C contacts close. When they close or short, they perform an internal reset for the Banner relay. In other words if one of the N/C contacts on either KM1 or KM2 don't close properly the Banner will not reset and will not work to power on the machine.

There are other possible problems, but most likely it's the Banner relay. I hope this helps you out!

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