Troubleshooting Switchmax®

Examples of how electrical signals route through the Switchmax system and some common fault condition routings can be found on the Switchmax Schematics tabs.

I.a. Two (2) KOR-LOK XLT/XHT System or Similar SPDT Mechanicals

1. CORES SET – Normal Indication

Indication: ALL AMBER LED LIGHTS ON
Output: SET SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES SET.

Set Power enters the Home Run port, travels through the Slide 1 splitter port, to the Slide 1 set switch (which is “on” because the cylinder is set & locked), then travels through the pull switch to confirm that it is in the “off” position, then to the Slide 1 AMBER LED. Power continues onward to the Slide 2 splitter port, through the switches in a similar fashion, and lights the Slide 2 AMBER LED. The signal then continues to the #3 port Jumper, and onward to output to the Press – SET SIGNAL WIRE.

CORES SET – Normal Indication

2. CORES PULLED – Normal Indication

Indication: ALL GREEN LED LIGHTS ON
Output: PULL SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES PULLED

Pull Power enters the Home Run port travels through the Slide 1 splitter port, to the Slide 1 Pull switch (which is “on” because the cylinder is retracted), then travels through the set switch to confirm that it is in the “off” position, then to the Slide 1 GREEN LED. Power continues onward to the Slide 2 splitter port, through the switches in a similar fashion, and lights the Slide 2 GREEN LED. The signal then continues to the #3 port Jumper, and onward to output to the Press – PULL SIGNAL WIRE.

CORES PULLED – Normal Indication

3. CORES SET or PULLED – NO LIGHTS

Indication: NO LIGHTS EITHER DIRECTION
Output: NONE

Possible Causes:

  1. POWER NOT CONNECTED or POWER CONNECTION REVERSED
    Typically during initial mold install in the press, power may be disconnected from the core pull circuit at the machine or at an alternate location from the mold plug. Some molds are set up with a plug that can be put in 180 degrees out of position.
  2. MISSING NEUTRAL VOLTAGE – INCORRECT NEUTRAL or GROUND
    The SWITCHMAX Junction Box is designed to operate with nominal 24 VDC power and requires a neutral 0 VDC connection relative to the Power Input for LED indication. If only the positive + power and signal wires are connected, it will provide the correct outputs for the press, but the LED’s will not light. Check for the press reading the cores inputs – it is likely that the Neutral wire connection is missing, incorrect – not off controller power.
  3. INCORRECT POWER – 110 VAC or 0 VDC systems
    While not particularly common, some presses operate on AC power, 110 VAC or similar. While the PFA XLT and XHT sensors can be operated at this voltage, the SWITCHMAX RJB is not designed for AC operation. Some press manufacturers provided zero voltage DC Power and inputs. While the RJB will pass these signals, there is no voltage for LED indication. Contact PFA for adaptors for these types of systems.
  4. CHECK SLIDES IN MID POSITION – NOT SET OR PULLED
    Typically during an initial tryout, something could be preventing the cores from reaching the fully pulled condition (in mold stops prevent the cylinder piston from reaching end of stroke) or something preventing the SET and LOCKED condition. For the SET indication, the cylinders must be properly adjusted and extended with adequate pressure to preload and lock for the lock to pass in front of the set switch and turn it “on”.
  5. CYLINDER CONTAMINATED WITH METAL
    New molds may have internal fluid passages with over drilled intersections or have off the shelf manifolds installed, which were not fully clean prior to connecting hydraulic components. Upon startup both Slide #1 sensors may be fouled and prevent any power from reaching the LED’s.
CORES SET or PULLED – NO LIGHTS

4. CORES SET – Normal Indication; CORES PULLED – Abnormal Indication – No lights.

Indication: ALL AMBER ON SET, NO LIGHTS ON PULL
Output: SET SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES SET. PULL SIGNAL WIRE – NOTHING

Possible Causes:

  1. CORE SLIDE #1 NOT PULLING
    Both cylinders are reading “LOCKED and SET”, but CORE SLIDE #1 may not be reaching the full retracted position. As a result, the switch does not turn “on” and the signal cannot pass to the GREEN LED and onward in the circuit
  2. SLIDE #1 SET Switch FAILED/CONTAMINTATION IN THE “ON” POSITION – STUCK “ON”.
    If the Side #1 front lock sensor fails to cycle due to being “STUCK” or “FAILED” in the ON position, the pull signal cannot pass as the path uses a common connection. This can be noticed by watching the Slide #1 AMBER LED STAY LIT while cylinders are in the mid stroke position and then going off when slide #1 reaches the pull position (turning the pull sensor on). Check the middle/front/rod end switch (set switch) for contamination or replace the sensor. If contaminated with metal – send the cylinder to PFA for evaluation/repair/cleaning and purge the hydraulic lines and system from contamination. If contaminated on initial mold change out, contamination is likely from contaminated hydraulic lines from previous mold. If upon initial mold tryout or early mold life startup, contamination may be from manifolds or hydraulic passages in the mold base.
CORES SET – Normal Indication; CORES PULLED – Abnormal Indication – No lights.

5. CORES SET – Abnormal Indication – No lights. CORES PULLED – Normal Indication

Indication: ALL GREEN ON PULL, NO LIGHTS ON SET
Output: PULL SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES PULLED. SET SIGNAL WIRE – NOTHING

Possible Causes:

  1. CORE SLIDE #1 NOT LOCKING/NOT SET
    Both cylinders are reading “PULLED”, but CORE SLIDE #1 may not be reaching the full extended and locked position. As a result, the sensor does not turn “on” and the signal cannot pass to the AMBER LED and onward in the circuit
  2. SLIDE #1 PULL SWITCH FAILED/CONTAMINATION IN THE “ON” POSITION – STUCK “ON”
    If the Side #1 back Pull switch fails to cycle due to being “STUCK” or “FAILED” in the ON position, the set signal cannot pass as the path uses a common connection. This can be noticed by watching the Slide #1 GREEN LED STAY LIT while cylinders are in the mid stroke position and then going off when slide #1 reaches the set and locked position (turning the set switch on). Check the back switch (pull switch) for contamination or replace the sensor. If contaminated with metal – send the cylinder to PFA for evaluation/repair/cleaning and purge the hydraulic lines and system from contamination. If contaminated on initial mold change out, contamination is likely from contaminated hydraulic lines from previous mold. If upon initial mold tryout or early mold life startup, contamination may be from manifolds or hydraulic passages in the mold base. 
CORES SET – Abnormal Indication – No lights. CORES PULLED – Normal Indication

6. CORES SET – Normal Indication; CORES PULLED – Abnormal Indication – BOTH LIGHTS

Indication: ALL AMBER ON SET, SLIDE #1 – BOTH AMBER & GREEN LIGHTS ON PULL
Output: SET SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES SET. PULL SIGNAL WIRE – NO SIGNAL.

Possible Causes:

  1. SLIDE #2 SET SWITCH FAILED/CONTAMINATION IN THE “ON” POSITION – STUCK “ON”.
    If the Side #2 front lock switch fails to cycle due to being “STUCK” or “FAILED” in the ON position, the pull signal travels through the SLIDE #1 SWITCHES correctly and lighting the #1 GREEN LED, but the signal while going through the Slide #2 Pull switch, it cannot pass the Slide #2 SET as the path uses a common connection. The power is routed instead through the stuck path to the Slide #1 AMBER LED resulting in both #1 SLIDE GREEN and AMBER Lights.
    The cause of the condition could be due to a failed switch or due to steel contamination on the sensor face. Check the middle/front/rod end switch (set switch) for contamination or replace the switch. If contaminated with metal – send the cylinder to PFA for evaluation/repair/cleaning and purge the hydraulic lines and system from contamination. If contaminated on initial mold change out, contamination is likely from contaminated hydraulic lines from previous mold. If upon initial mold tryout or early mold life startup, contamination may be from manifolds or hydraulic passages in the mold base.
CORES SET – Normal Indication; CORES PULLED – Abnormal Indication – BOTH LIGHTS

7. CORES PULLED – Normal Indication; CORES SET – Abnormal Indication – BOTH LIGHTS

Indication: ALL GREEN ON PULL, SLIDE #1 – BOTH AMBER & GREEN LIGHTS ON SET
Output: PULL SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES PULLED. SET SIGNAL WIRE – NO SIGNAL.

Possible Causes:

  1. SLIDE #2 PULL SWITCH FAILED/CONTAMINATION IN THE “ON” POSITION – STUCK “ON”.
    If the Side #2 Pull switch fails to cycle due to being “STUCK” or “FAILED” in the ON position, the set signal travels through the SLIDE #1 SWITCHES correctly and lighting the #1 AMBER LED, but the signal while going through the Slide #2 Set switch, it cannot pass the Slide #2 PULL as the path uses a common connection. The power is routed instead through the stuck path to the Slide #1 GREEN LED resulting in both #1 SLIDE GREEN and AMBER Lights.
    The cause of the condition could be due to a failed switch or due to steel contamination on the sensor face. Check the back end switch (pull sensor) for contamination or replace the switch. If contaminated with metal – send the cylinder to PFA for evaluation/repair/cleaning and purge the hydraulic lines and system from contamination. If contaminated on initial mold change out, contamination is likely from contaminated hydraulic lines from previous mold, manifolds or hydraulic passages in the mold base.
CORES PULLED – Normal Indication; CORES SET – Abnormal Indication – BOTH LIGHTS

8. CORES SET – ALL AMBER + any GREEN (OR) CORES PULLED – ALL GREEN + any AMBER

Indication: ALL AMBER + any GREEN (OR) ALL GREEN + any AMBER
Output: SET SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES SET when SET PULL SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES PULL when PULLED

Possible Causes:

  1. SHORT CONDITION IN SENSOR, RJB, SPLITTER CABLE, OR PLUG ENDS – FIELD WIREABLE CONNECTORS INSTALLED AND WIRES TOUCHING INSIDE MANUAL WIRING TERMINAL LOCATION.
    If the Normally Open (NO) and Normally Closed (NC) wires contact the COMMON wire in any of the components, a 3-WAY short is created sending power signals to multiple locations and LED lights.
    PFA thus recommends the use of redundant core retract sensing in the event of sensor failures, rod to core separation, or other unexpected circumstances.
CORES SET – ALL AMBER + any GREEN (OR) CORES PULLED – ALL GREEN + any AMBER

9. CORES SET – ALL AMBER AND GREEN (OR) CORES PULLED – ALL GREEN AND AMBER

Indication: ALL AMBER + GREEN (OR) ALL GREEN + AMBER
Output: SET SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES SET when SET
PULL SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES PULL when PULLED

Possible Causes:

  1. POWER IS REVERSED FOR THE SET WIRES AND PULL WIRES ONLY
    If the plugs used for the SWITCHMAX RJB connection are split to three separate connections, Neutral, “set plug”, and “pull plug”, it is possible that the Neutral is correct and the Set and Pull plugs or wires are connect opposite of the normal connection. Thus the power wire has the signal connection and the signal wire has power on it, effectively trying to power the RJB backwards.
    THIS CONDITION MAY LOOK SIMILAR TO THE SHORT SCENARIO, but is EASY TO IDENTIFY AS IT HAPPENS WHEN THE MOLD IS INITIALLY INSTALLED.
CORES SET – ALL AMBER AND GREEN (OR) CORES PULLED – ALL GREEN AND AMBER

II.a. Two (2) KOR-LOK PNP system - or similar PNP Sensors

1. CORES SET – Normal Indication

Indication: ALL AMBER LED LIGHTS ON
Output: SET SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES SET.

Set Power enters the Home Run port, travels through the Slide 1 splitter port, to the Slide 1 set sensor (which is “on” because the cylinder is set & locked), then travels through the pull sensor to confirm that it is in the “off” position, then to the Slide 1 AMBER LED. Power continues onward to the Slide 2 splitter port, through the sensors in a similar fashion, and lights the Slide 2 AMBER LED. The signal then continues to the #3 port Jumper, and onward to output to the Press – SET SIGNAL WIRE.

CORES SET – Normal Indication

2. CORES PULLED – Normal Indication

Indication: ALL GREEN LED LIGHTS ON
Output: PULL SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES PULLED

Pull Power enters the Home Run port travels through the Slide 1 splitter port, to the Slide 1 Pull sensor (which is “on” because the cylinder is retracted), then travels through the set sensor to confirm that it is in the “off” position, then to the Slide 1 GREEN LED. Power continues onward to the Slide 2 splitter port, through the sensors in a similar fashion, and lights the Slide 2 GREEN LED. The signal then continues to the #3 port Jumper, the Expansion port jumper, and to the Press – PULL SIGNAL WIRE.

CORES PULLED – Normal Indication

3. CORES SET or PULLED – NO LIGHTS

Indication: NO LIGHTS EITHER DIRECTION
Output: NONE

Possible Causes:

  1. a. POWER NOT CONNECTED or POWER CONNECTION REVERSED
    Typically during initial mold install in the press, power may be disconnected from the core pull circuit at the machine or at an alternate location from the mold plug. Some molds are set up with a plug that can be put in 180 degrees out of position.
  2. MISSING NEUTRAL VOLTAGE – INCORRECT NEUTRAL or GROUND
    The SWITCHMAX Junction Box is designed to operate with nominal 24VDC power and requires a neutral 0 VDC connection relative to the Power Input for LED indication. IF only the positive + power and signal wires are connected, it will not function, because PNP sensors require a neutral voltage (0 VDC) to operate. Neutral may be missing or not from the control power connector.
  3. INCORRECT POWER – 110 VAC or 0 VDC systems
    While not particularly common, some presses operate on AC power, 110 VAC or similar. The SWITCHMAX RJB is not designed for AC operation. Some press manufacturers provided zero voltage DC Power and inputs. While the RJB will pass these signals, there is no voltage for LED indication. Contact PFA for adaptors for these types of systems.
  4. CHECK SLIDES IN MID POSITION – NOT SET OR PULLED
    Typically during an initial tryout, something could be preventing the cores from reaching the fully pulled condition (in mold stops prevent the cylinder piston from reaching end of stroke) or something preventing the SET and LOCKED condition. For the SET indication, the cylinders must be properly adjusted and extended with adequate pressure to preload and lock for the lock to pass in front of the set sensor and turn it “on”.
CORES SET or PULLED – NO LIGHTS

4. CORES SET – Normal Indication; CORES PULLED – Abnormal Indication – No lights.

Indication: ALL AMBER ON SET, NO LIGHTS ON PULL
Output: SET SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES SET. PULL SIGNAL WIRE – NOTHING

Possible Causes:

  1. CORE SLIDE #1 NOT PULLING – NOT READING
    SLIDE #1 may not be reaching the fully retracted position. As a result, the sensor does not turn “on” and the signal cannot pass to the GREEN LED and onward in the circuit
  2. SLIDE #1 PULL SENSOR DAMAGED
    If the pull sensor is not working for position #1, there will be no lights for pull.
CORES SET – Normal Indication; CORES PULLED – Abnormal Indication – No lights.

5. CORES SET – Abnormal Indication – No lights. CORES PULLED – Normal Indication

Indication: ALL GREEN ON PULL, NO LIGHTS ON SET
Output: PULL SIGNAL WIRE at SUPPLY VOLTAGE (24VDC typical) – CORES PULLED. SET SIGNAL WIRE – NOTHING

Possible Causes:

  1. CORE SLIDE #1 NOT SET – NOT READING
    Slide #1 may not be reading the fully extended position or locked position. As a result, the sensor does not turn “on” and the signal cannot pass to the AMBER LED and onward in the circuit
  2. SLIDE #1 SET SENSOR DAMAGED
    If the set sensor is not working for position #1, there will be no light for set. For locking cylinders (KOR-LOK®) preload may be incorrect. One cylinder not locking – check setup/preload.
CORES SET – Abnormal Indication – No lights. CORES PULLED – Normal Indication

6. CORES SET – Normal Indication; CORES PULLED – Abnormal Indication – BOTH LIGHTS

Indication: ALL AMBER ON SET, SLIDE #1 – BOTH AMBER & GREEN LIGHTS ON PULL
Output: NORMAL – JUST EXTRA AMBER LIGHT WHEN CORES PULLED.

Possible Causes:

  1. Ready target – metal in front of sensor.
  2. Damaged sensor – short.
CORES SET – Normal Indication; CORES PULLED – Abnormal Indication – BOTH LIGHTS

7. CORES PULLED – Normal Indication; CORES SET – Abnormal Indication – BOTH LIGHTS

Indication: ALL AMBER ON SET, SLIDE #1 – BOTH AMBER & GREEN LIGHTS ON PULL
Output: NORMAL – JUST EXTRA green LIGHT WHEN CORES set.

Possible Causes:

  1. Ready target – metal in front of sensor.
  2. Damaged sensor – short
CORES PULLED – Normal Indication; CORES SET – Abnormal Indication – BOTH LIGHTS

For additional troubleshooting assistance or questions on your Switchmax system, please contact a PFA Applications Specialist.