DIGITAL MANIFOLDS
Digital manifolds and smart devices E
lectronic measuring instruments for pressure and temperature as well as digital manifolds are well established on today’s market, with
leading manufacturers offering entire series in their product ranges. Requirements vary around the world – some refrigeration technicians rely on tried-and-tested devices while others prefer to use the latest technologies. And it’s important to meet both types of needs. The most important features of electronic measuring devices have been established in broad-based customer surveys and are discussed in more detail in this article. A survey of 600 digital product users has revealed the features considered most important in a digital manifold. From this, refrigeration technicians consider accuracy and user-friendliness to be the most desirable features in a digital manifold.
The display value should obviously deviate only
minimally from the effective value. However, accuracy of 0.5% is more than sufficient when installing a refrigeration system. The accuracy of pressure sensors on a manifold is specified as full-scale accuracy. Therefore, the measured value may deviate by 0.25 bar from the effective value in a scale range of 0-50 bar, which results in a maximum temperature deviation of +/- 1°C in the calculated evaporation temperature for R410. Furthermore, users shouldn’t be dazzled by an unnecessarily high number of digits after the decimal point. What’s more important is the accuracy of the pressure measurement technology, which is achieved using instrument- specific calibration and reliable compensation for temperature influences. An intuitive user guide helps refrigeration
technicians to quickly familiarise themselves with the manifold and to organise their workload efficiently. Frequently used controls can be activated quickly with just a few clicks. And when a device offers lots of functions, smart menu navigation is required. A digital manifold is used continuously over several years. Therefore, it’s likely that sometimes it will be dropped, given a good shaking while in the service vehicle and used regularly with dirty gloves. The unit will also be exposed to occasional spray water, although it’s not designed for underwater use. So obviously the components chosen for use in the manifold must be extremely robust and durable.
20 December 2019
A leading supplier of refrigeration tools and components, REFCO talks about exactly what refrigeration technicians need when it comes to manifolds.
A manifold must also be able to adapt to rapidly
changing legal requirements. For example, it must be possible to update refrigerants following their release by the manufacturer, while firmware updates introducing new functions are essential. Wear parts must be readily available and easy to replace.
From the refrigeration technician’s point of view, durability also means that they can keep the manifold for a long time: an anti-theft mechanism protects the device during long-term use. The device must remain operational and
functional even in varying and demanding environmental conditions, something only push buttons can guarantee. Faced with environmental conditions that range from very low temperatures in deep-freeze systems to roof installations at >40°C, and the use of bare hands and dirty gloves, any touch display will reach its limits. An impact-resistant case helps protect against shocks and vibrations. The soft surface of the device itself also absorbs shocks and makes it pleasant to handle. Everybody’s talking about IoT. It’s led to
manufacturers offering devices with Bluetooth Low Energy (BLE) together with a free app for mobile devices. But what are the benefits of these apps for refrigeration technicians? If the apps simply display the same values as the manifold and allow the units to be set, then they are no more than gimmicks. The units will be adjusted by a technician at most once, during commissioning. An app is only really useful to refrigeration
technicians if they can record the measurement data that they generate using the manifold in a report. Ideally, all devices required for reporting would be connected via BLE and all relevant data collected in one report per installation or maintenance job. This would allow refrigeration technicians to quickly demonstrate the value of their service to their customer, save time and give them access to years’ worth of maintenance data. It also means that reports could be created seamlessly from several media sources. This way of working will significantly change how services are provided – refrigeration technicians need to make sure they keep pace with these new developments. Refrigeration systems often have no access to a mobile network, and mobile devices or service tablets are not always charged, which means that it must be possible to connect multiple devices even without a mobile device. Measuring
instruments that don’t display the measured values are therefore no use. Superheat and subcool values need reliable refrigerant data to be calculated correctly, helping the refrigeration technician to get the best out of the refrigeration system for normal operation. This should also be easily possible for a combined system with cooling and heat pump. The refrigeration technician should be able to check the superheat and subcool values without having to disconnect and reconnect the hoses. Before filling, a refrigeration circuit must be correctly evacuated and the successful evacuation confirmed by the vacuum measurement. Some manifolds have cabled vacuum sensors. The vacuum measurement must be taken at the point on the refrigeration circuit furthest from the connection point of the vacuum pump, resulting in a big enough reach from the manifold to the vacuum measuring point. The range of the cables is often too small. A wireless vacuum gauge solves this problem.
The above-mentioned features of today’s digital manifolds offer significantly more value to refrigeration technicians than those of earlier- generation manifolds. When comparing manifold prices, the scope of delivery should always be taken into account – some sets include vacuum and temperature sensors or temperature clamps and various models of hoses in addition to the manifold itself.
REFMATE digital manifold by REFCO I
n spring 2019, REFCO launched its new digital manifold, which has incorporated the findings from the above survey. As always, the Swiss product combines high accuracy, quality and reliability. Patented analogue display Large 4.3-inch TFT colour display Superheat and subcool indicator Buttons for intuitive control High precision – accuracy class 0.5 Flexible power supply – AA batteries or USB port
Wireless communication with app and other devices
Lockable for long-term measurements The device also comes with the free REFMESH Android or iOS app.
www.acr-news.com
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