GMC Mold Temperature Controller  
Issues > Check/Troubleshooting
Pump pressure does not decrease.
  1. Feeding or Return valves for medium is closed.
  2. Loss of pressure in pipings.
  3. Pressure gauge not functioning.

1. Feeding or Return valves for medium is closed.
Start inspection after five hours, when valves cool down naturally. Immediately after stopping operations, unit and medium temperatures will be very high.
  1. Check opening or closing of both feed and return valves.

    [Point]
    Too much pressure will be applied to the pumps when running fully closed.
    Watch open/close condition of valves.
If problem persists
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2. Loss of pressure in pipings.
  1. Use larger diameter pipes and change its routes. Install bypasses on pipings.
If problem persists
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3. Pressure gauge not functioning.
  1. Check to see if gauge functions when unit is stopped or operating. Then compare.


    (References)
    Pump Pressure:
    Use unit with pressure set below specified value.
    Adjust pressure with pressure adjusting valve located at the back of the unit.
    Specified Pressure
    Units Set Pressure (50 Hz/60 Hz)
    25 Series 0.40MPa
    55 Series 0.40MPa
    88 Series 0.40MPa

    When set below 85 degrees C, uses of L, LL or H-type will be affected by drain-side pressure (back pressure) or feed pressure.
    Therefore:
    (Pressure gauge value of unit) = (pump pressure) + (back or feed pressure). To obtain actual pump pressure value, subtract the back pressure and feed pressure from the pressure gauge value.
    * Effects of the cooling water feed pressure can be observed by increasing pressure and moving the indicator of the gauge in a clockwise direction when the heater electromagnetic switch is off (in cooling mode). Back pressure will be indicated on the pressure gauge when the unit is stopped.

    When set above 85 degrees C, use of H-type will be affected by increased water temperatures in the tightly closed circuit.
    Therefore:
    (Pressure gauge value of unit) = (pump pressure) + (steam pressure of water). To obtain actual pump pressure value, subtract the steam pressure of water from the pressure gauge value.
    Steam pressure will be indicated on the pressure gauge when unit is
    temporarily stopped.
Pressure Gauge Order
If problem persists
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