Series DHII Digihelic® Differential Pressure Controller
NEMA 4 (IP66) Housing with Large, Bright LCD, Square Root Output for Flow
The Series DHII Digihelic® Differential Pressure Controller takes all the features of the standard Digihelic® Pressure Controller 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 display that can easily be seen 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 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 is utilized in maintaining plant cleanliness.
NIST CALIBRATION available in Product Configurator.
- Air Handlers
- Clean Rooms
Models & Ordering
- Air and non-combustible, compatible gases.
- Wetted Materials:
- Consult factory.
- Housing Material:
- Aluminum, glass.
- ±0.5% at 77°F (25°C) including hysteresis and repeatability (after 1 hour warmup).
- < ±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).
- 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.
- 2 lb 10 oz (1.19 kg).
- Serial Communications:
- Modbus® RTU, RS485, 9600 Baud.
- Agency Approvals:
- CE, UL.
- SWITCH SPECIFICATIONS
- 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
|Model Number||Description||Usually Ships*||Price||Order|
|A-438||Surface mounting bracket.||1-2 Weeks||$15.00||Order|
|MN-1||Mini-Node™ RS-485 to USB converter.||Same Day||$91.50||Order|
|DIGIHELIC LINKS||Communication software CD.||Same Day||$70.50||Order|
|A-489||4" 303 SS straight static pressure tip with flange, 1/4" hose barb.||Same Day||$8.50||Order|
|A-301||Static pressure tip, for 1/4" metal tubing connection.||Same Day||$11.75||Order|
|A-302||Static pressure tip, for 3/16" and 1/8" ID plastic or rubber tubing.||Same Day||$11.00||Order|
|A-302F-A||303 SS Static pressure tip with mounting flange, for 3/16" I.D. rubber or plastic tubing. 4" insertion depth, includes mounting screws||Same Day||$11.00||Order|
|EXAMPLE||DHII||002||NIST||Series DHII-002-NIST Digihelic® Differential Pressure Controller, range 0.25" w.c., with NIST Traceable Calibration Certificate.|
|SERIES||DHII||Digihelic® Differential Pressure Controller|
|Certificate of Origin
NIST Traceable Calibration Certificate
- A customer would like to get switching capability, local pressure indication, and a 4-20 mA output signal all in one device. Do we have a product to offer them?
- Yes. The DH, DHII or DH3 possess high/low set points, digital gage display and 4-20 mA full scale output signal for air and compatible gas. The EDA, DPG-200, DPT and the MDPC possess high/low set points, digital gage display and 4-20 mA full scale output signal for compatible fluids.
- Your Magnehelic gauge doesn't come with a calibration certificate, do you have any documentation for these gauges to meet these needs?
- We have 3 options: (1) We can supply a Certificate of Conformance at no charge if you request that certificate at the time of order. The Certificate of conformance would state that each Magnehelic gauge is calibrated to meet the specifications stated on the spec sheet. (2) We offer a factory calibration “-FC” as an option that is a certificate of the standard calibration points at the time of manufacture, for a small fee. (3) We can also provide a NIST-traceable calibration for an extra charge per gage if that is required. To get the NIST-traceable calibration, you would simply add a “-NIST” to the end of your part number. NIST-traceable calibrations will come with the 6 point calibration certificate. We recommend “periodic calibration” for our Magnehelic, though we leave the specific time-frame up to the end user, since different organizations have different requirements (i.e. government groups often require more frequent calibrations.) If you choose to have the NIST traceable calibration done, the NIST group (the National Institute of Standards and Technology) dictates yearly calibration and it will be printed on the certificate.
- Looking for information on the RS-232 Serial Communications Digihelic Links™ Communications Software, Modbus protocol®. Specifically command format, commands available, and controller responses?
- Click on Modbus® to download this list of protocol.
- I am using DH3 Digihelic differential pressure controllers for my applications. The instruction says that "the Alarm can be reset by the RESET key on the front panel, or an external reset switch". For the second case (reset by external reset switch), could you let me know how to do it? The instruction doesn't provide any related detail. Thanks in advance.
- Unfortunately, contrary to what was printed in the instruction manual, the DH3 does not have the ability for the alarm to be reset via an external reset switch, mainly due to the limited number of pins available in the electrical connector. This feature is only available in the DH and DHII series Digihelics.
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