Extreme Environment Home Assistance Sensors #2 Hammond IP68 Enclosure and Circular Connectors
For Extreme Environment Home Assistance Sensors
Table of Contents
1 Introduction
Experiment with Extreme Environment challenge, experiments to test the enclosure under various extreme environments.
In center, is the Hammond IP68 Enclosure and accessories, including water-tight circular connector. This blog shall explain how it works.
The specification of the Polycarbonate & General Purpose ABS Enclosures is with RAL7035 grey polycarb plastic watertight enclosure, clear lid. With size ( L x W x H) of 9.4 in x 6.3 in x 3.5 in(239 mm x 160 mm x 89 mm), and Shipping Weight of 1.35 lbs (0.61 kg)
It is REACH Compliant and RoHS Compliant. The Flame Rating is UL94 V-0 and IP Rating is IP68. It conforms to NEMA Rating 4, 4X, 6, 6P, 12 & 13.
For inner part, the Max. P.C. Board Length is 145.5mm and Max. P.C. Board Width is 226.82mm.
2 Sizing
According to 1554VA (farnell.com), the sizing shall be
The enclosure include one transparent front lid and one bottom box. When measure the size, the value different from above diagram.
For bottom box, the upper part is oversize, slightly bigger than 240mm
close look
For bottom base, slightly smaller than 240mm,
close look,
The size of front lid is conform to ratings, that is 240mm exactly
close look.
Ditto to that of width, which is 160mm,
The situation explain what I have happened when I hand-cut Inner PCB support Panel. First I draw carton frame from upper part of the bottom box, the cut panel can not go to lower part of the box. It stuck in the middle.
It is assumed that, it is help to put PCB in and out easily.
3 Accessories
Accessories are important for functional of this IP68 enclosure, the gasket seal the space for front lid and bottom box, the tighten screw push front lid and bottom box together. Here are some list of replacement parts and Accessories
3.1 gasket
As shown in unboxing blog, the gasket is continuously rubber seal with square section , as per 1554VAGASKET.pdf (hammfg.com)
with diagram
As comparation, Here is another so-called water-tight enclosure with round rubber band,
Put the gasket together,
look close to compare the section
The installation of the gasket is totally different, for the comparing white one, the rubber line shall be overlap and cut, small gap is inevitable,
The result can be obvious, the IP grade can be different.
3.2 screws
There are four screws to fix the front lid and bottom box, take close look to the different
The spiral is not throughput for Hammond IP68 Enclosure, Let us go to the two small video clips
And
This can secure the screw from scatter during assembly.
Another screw for the enclosure fixing, four screw and nut sets shall be used
Put the nut into this slot
With the help of one pencil, it can be tightened
This different from fixing solution by Hammnd(1554FOOT WEB INSTRUCTION) not included in DEV kit, which is much better
3.3 Inner panel for PCB support
As per 1554VAPL.pdf (hammfg.com),
This is my hand-cut version with detour from carton sheet, it works as well,
3.4 Optional Plastic mounting feet for enclosure support 1554FT - Hammond Mfg. (hammfg.com) are not included,
3.5 Optional Pole Mount Kit as per PMB110127KIT2 - Hammond Mfg. (hammfg.com) is not included.
4 Connector
As per 2688495.pdf (farnell.com), here is how the connector is assembled and plugged in
According to the specification, this connector is IP67 HARSH INDUSTRIAL CONNECTORS, not IP68 as enclosure is.
The locking is quick release metal latches. Specially for Panel mount. IP67 is dust proof and is durable to be immersed under water for 30 minutes.
The following material is fire-proof,
Contacts: Copper Alloy with gold flash over 50μ” (1.27μm) min. Nickel
Housing: Engineering thermoplastic, UL94V-0 rated, Black
Metal Shell: Die cast Zinc alloy, chrome plated
The contact can withstand 500V AC and rated current of 5A. Fit for outdoor environment with Operating Temperature range from -55°C to +105°C and withstand Salt Spray 250 hours Per EIA364-26, 250 Hrs
5 IP68 and watertight
The most important specification for THE enclosure is IP grade. An IP rating is a certification proving a product meets a certain standard of water and dustproofing/resistance. The standards are set by the IP Code, or Ingress Protection Code, IEC standard 60529, (also known as the International Protection Code).
From above explanation, IP 68 is highest application in harsh environment. Except IP69 which is used in submersible motor or submarine.
6 Material and NEMA Rating
NEMA is a rating system for equipment that might be exposed to liquids, rain, ice, corrosion and contaminates such as dust. The following explain NEMA Rating 4, 4X, 6, 6P, 12 & 13.
Type 4: Weather tight (weatherproof) enclosures. to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, and hose-directed water. NEMA 4X is used when protection from the worst environments is required.
Type 4X: Same as Type 4 except constructed from corrosion-resistant material to provide a degree of protection against exposure to corrosive agents such as salt spray.
Type 12: Constructed (without knockouts) for indoor use to provide a degree of protection to personnel against access to hazardous parts. Provides a degree of protection of the equipment inside the enclosure against ingress of solid foreign objects (falling dirt and circulating dust, lint, fibers, and fyings). Also provides a degree of protection with respect to harmful effects on the equipment due to the ingress of water (dripping and light splashing). Nema Enclosures produce NEMA 12 enclosures which are intended mainly for indoor industrial, manufacturing, and machining applications.
As this diagram shows
7 Here is suggested experiments
7.1 Continuously humidity, dusty, vibration ingressive experiment
7.2 Salt spray experiment for 250 hours
7.3 NEMA experiment of 10 second burning twice without any flame or fire.
8 Summary
The IP68 Hammond Enclosure are durable in harsh environment and provide idea protection for electronics part and PCB .
Reference
[1] 1554VA2GYCL IP 68 Enclosure - Hammond Mfg. (hammfg.com)
[2] 1554VA IP 68 Enclosure Diagram
[4] IP67 vs IP68: Waterproof IP ratings explained
[5] NEMA Ratings Buying Guide for Type 1, 3R, 4, 4X, 12 Differences | NEMA Enclosures
[6] FR4 Laminate With UL94 V-0 And UL94 HB
