Watlow 935 Kits

This controller can be used on both 110V and 220V systems, both in the US and internationally. It is easily configured for either Fahrenheit or Celsius operation (we will set it up appropriately based on your location or preference).

In our view, the strengths of the 935 are:

• Like all Watlow controllers, we can perform a hardware recalibration prior to shipment. This assures the customer of accurate temperature readings.
• The 935 responds very quickly to temperature changes.
• It offers a very clean, uncluttered display that we think is very attractive.

The 935A has a single line display, on which is displayed the current thermocouple reading. Viewing the set point requires a single button press. Changing the set point requires pressing and holding the SET button, and then using the UP and DOWN arrow buttons to adjust the set point.

Aside from not simultaneously displaying current temperature and setpoint, the minor weakness we see in the 935 is closely associated with its fast temperature response. The 935 tends to allow the boiler temperature to oscillate a little more than other Watlow controllers when idling.

This has absolutely no effect on shot temperature (we have measured it to confirm), as the actual temperature oscillation is usually no more than +/- 0.5F (std deviation is actually 0.3F). But the displayed temperature on the 935 will generally not remain as "locked" on setpoint as our other Watlows (although the display variation is never more than +/- 1F).

• On all versions of the 935, OT2 can be configured as a timer. Paul Szilard, an Aussie customer with a good electronics background, has successfully adapted this feature to act as an automatic 25 sec. shot timer on his Silvia. Then Max (who is in Taiwan) did the same timer mod on his Silvia/935, and provided this video.