Last Updates: 18/04/2021

Dwyer Series DHII Digihelic® Differential Pressure Controller

The Dwyer Series DHII Digihelic® Differential Pressure Controller takes all the standard Digihelic® Pressure Controller features and packages them in a robust NEMA 4 (IP66) housing.

The Digihelic® II Pressure Controller combines the 2 SPDT control relays, 4-20 mA process output, and Modbus® communications with a large, brightly backlit 4 digit LCD DHII Digihelic can easily see from long distances. The electrical wiring has also been enhanced in the DHII with its detachable terminal blocks. The removable terminals allow the install to easily wire the terminal block outside the housing and then attach it to the circuit board, reducing wiring difficulties and installation time on the process.

The Digihelic® II Differential Pressure Control in the NEMA 4 (IP66) enclosure enables this product to be the perfect choice when mounting pressure controls outdoors in such applications as rooftop air handlers. This housing also makes it the ideal solution for surface mounting in clean rooms or facilities where water or a cleaning solution maintains plant cleanliness.

Product Applications

  • Air Handlers
  • Clean Rooms

Service : Air and non-combustible, compatible gases.

Wetted Materials : Consult factory.

Housing Material : Aluminum, glass.

Accuracy : ±0.5% at 77°F (25°C) including hysteresis and repeatability (after 1 hour warmup).

Stability : < ±1% per year.

Pressure Limits : Ranges ≤ 2.5 in w.c. = 2 psi; 5″: 5 psi; 10″: 5 psi; 25″: 5 psi; 50″: 5 psi, 100″: 9 psi.

Temperature Limits : 32 to 140°F (0 to 60°C).

Compensated Temperature Limits : 32 to 140°F (0 to 60°C).

Thermal Effects : 0.020%/°F (0.036/°C) from 77°F (25°C).

Power Requirements : High voltage power = 100 to 240 VAC, 50 to 400 Hz or 132 to 240 VDC; Low voltage power = 24 VDC ±20%.

Power Consumption : Low voltage power = 24 VDC – 130 mA max; High voltage power = 100 to 240 VAC, 132 to 240 VDC – 7 VA max.Output Signal:4-20 mA DC into 900 Ω max.

Zero & Span Adjustments : Accessible via menus.

Response Time : 250 ms (dampening set to 1).

Display : 4 digit backlit LCD 0.6″ height. LED indicators for set point and alarm status.

Electrical Connections : Euro type removable terminal blocks with watertight conduit fittings for 1/2″ watertight conduit.

Process Connections : 1/8″ female NPT.

Enclosure Rating : Designed to meet NEMA 4 (IP66).

Mounting Orientation : Mount unit in horizontal plane.

Weight : 2 lb 10 oz (1.19 kg).

Serial Communications: Modbus® RTU, RS485, 9600 Baud.

Agency Approvals: CE, UL.


Switch Type: 2 SPDT relays.

Electrical Rating: 8 amps at 240 VAC resistive.

Set Point Adjustment: Adjustable via keypad on face.

  • NEMA 4 housing enables a range of uses both outdoors or indoors where water is present
  • Large backlight LCD display provides local reading from a distance
  • Detachable terminal blocks reduce wiring difficulties saving installation time

Manual: Instruction Manual
Catalog Page: Series DHII Catalog Page

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