--- title: "Max Zs Values - Reviews, Revenue and Downloads in United Kingdom | Apple App Store" description: "Calculate and look up the maximum permitted Zs value ( earth loop impedance ). Max Zs Values also includes the 80% temperature adjusted values and a some MCCB 60947-2 manufacture Zs charts. - 100% BS" --- # Max Zs Values — United Kingdom > Zs Values 18th Edition BS 7671 ![Max Zs Values App Icon](https://is1-ssl.mzstatic.com/image/thumb/Purple221/v4/86/4f/83/864f8382-044b-59ef-5a8e-0dd6eb261560/AppIcon-1x_U007emarketing-0-11-0-0-85-220-0.png/434x0w.png) **Developer:** [Pro Certs Software](https://apptail.io/developer/pro-certs-software-BpE) (United Kingdom) **Category:** Reference **Rating:** 4.2/5 (20 ratings) **Price:** Free **Bundle ID:** com.pro-certs.zsvalues **Store:** Apple App Store **Country:** United Kingdom **Version:** 3.1.18 (released 2025-07-29) **Original Release:** 2012-02-12 **Languages:** English **App Store Link:** [Download on Apple App Store](https://apps.apple.com/gb/app/app/id498838137) **AppTail Page:** [https://apptail.io/app/max-zs-values-Ynae/united-kingdom](https://apptail.io/app/max-zs-values-Ynae/united-kingdom) ## Max Zs Values Description Calculate and look up the maximum permitted Zs value ( earth loop impedance ). Max Zs Values also includes the 80% temperature adjusted values and a some MCCB 60947-2 manufacture Zs charts. - 100% BS 7671 Zs Values - 80% On Site Guide Zs Values - 0.4 (s) second disconnection times - 0.2 (s) second disconnection times - 5 (s) second disconnection times - Common BS EN Devices: Scroll through the list of protective devices and select the device rating to calculate the maximum permitted Zs value for your selected protective device and rating combination. - 60947-2 MCCB's Zs Tables: Look up the maximum permitted Zs tables for a selection of MCCB manufacture devices (some). - Maximum Zs Features: + Maximum Disconnection Times + BS 7671 18th Edition Zs Tables + Fuse's + MCB's + RCBO's + RCD's in TT earthing systems + Max REC Ze values + 100% values + 80% values + 0.4 second disconnection times + 0.2 second disconnection times + 5 second disconnection times + Uo 55v (U 110v) single phase and Uo 63.5v (three phase) Zs values + BS EN 60947-2 MCCB manufacture device charts (some) There is now a new "Zs Converter" to convert old Zs values to the new 18th edition 230v Cmin Zs values. Check out our collection of electrical apps such as the "Pro Certs" Electrical Certification App for iPad. ## Max Zs Values Screenshots - [Screenshot 1](https://is1-ssl.mzstatic.com/image/thumb/Purple122/v4/e8/a3/3e/e8a33e80-f8d1-a436-5c77-766e9c36337b/c51f9f69-dc51-4df4-b7cf-6407930df11e_CommonDevices.png/1242x2688.png) - [Screenshot 2](https://is1-ssl.mzstatic.com/image/thumb/Purple112/v4/c7/d8/ff/c7d8ff4f-2dd3-0b1a-bacf-38d8ea2c7b3c/81ec3c8c-229d-4045-8cbc-d4f32a3a60f6_ManuDevices.png/1242x2688.png) - [Screenshot 3](https://is1-ssl.mzstatic.com/image/thumb/PurpleSource112/v4/ce/c8/7f/cec87f64-f6cd-e3f3-fb7b-be21db8aca88/c23f9c88-ff14-4620-b756-3dc5b0ffd11d_Home1.png/1242x2688.png) - [Screenshot 4](https://is1-ssl.mzstatic.com/image/thumb/Purple122/v4/99/a8/ae/99a8ae75-a83f-cda3-0a31-7dfa7fd54cf8/77c07f8a-84ee-4cd5-b90f-a7b3031c7856_Uo55V.png/1242x2688.png) - [Screenshot 5](https://is1-ssl.mzstatic.com/image/thumb/Purple112/v4/5e/19/66/5e196679-18dd-4100-0383-209433214485/08dfb494-57bb-4871-9d41-aa5f6d17f62d_DocViewer.png/1242x2688.png) - [Screenshot 6](https://is1-ssl.mzstatic.com/image/thumb/Purple112/v4/8b/13/f0/8b13f06b-47a7-ef10-3529-e3c45cd7c65b/5c7d8e46-175f-41da-b0f7-d9a4f4dae575_ZsResults.png/1242x2688.png) - [Screenshot 7](https://is1-ssl.mzstatic.com/image/thumb/Purple122/v4/35/1d/91/351d910b-a760-1b47-8d0c-64cf2b55576d/f8fac365-94c5-451a-8e9c-a6b5ddcfc335_DNOZe.png/1242x2688.png) - [Screenshot 8](https://is1-ssl.mzstatic.com/image/thumb/Purple112/v4/9f/55/2b/9f552b74-6955-016c-8a69-8cd4d68aa8fa/0db7e211-5780-4e7b-af41-58ffb82924bc_RCDTT.png/1242x2688.png) - [Screenshot 9](https://is1-ssl.mzstatic.com/image/thumb/Purple112/v4/f0/b5/85/f0b58555-f7f3-9055-2d8d-95408b70b33f/bb0aef44-7c7b-4c29-847c-6e76fed12e11_Home_with_Menu.png/1242x2688.png) ## Max Zs Values Rating Breakdown in United Kingdom - 5 stars: 13 (65%) - 4 stars: 4 (20%) - 3 stars: 0 (0%) - 2 stars: 0 (0%) - 1 stars: 3 (15%) ## Max Zs Values Reviews in United Kingdom ### *---- "Unhappy long standing customer" Really unhappy that I have purchased this app previously at nearly £10 - had it for years, used it often. Purchased a new phone and I’ve had to repurchase it. Even though I’ve used the same email address to repurchase. I feel like that is unfair. -- shanisnel, 2023-07-11 ### *---- "Rip off" Really poor app -- Mjbunsen, 2023-06-14 ### ***** "Essential for commissioning." I have had this app for a few years and the update is amazing!!!! Everything is always up to date, easy to use l. has many variety of MCB, fuses and MCCBs values available. Well done to whoever made it. -- Tigga man, 2023-04-19 ### ****- "Insightful" No, not Mccb’s but type 4 3871. Seeing that you had the Mccb’s gave me hope for the 3871’s Other than that it’s a great app. Bad mood, sorry for the gut reaction. -- Versys-rider, 2021-08-18 ### ***** "Cert Time Saver" Brilliant app. Saves valuable time when fillling out certs especially for MCCB max zs. Awesome. -- 2LateMickey, 2021-07-15 ### ***** "Give it a go" I couldn’t find a Zs reading for a breaker so I brought this app and I’m very impressed by it. Will be very handy on site for doing periodic’s -- sa dvgfbnhg, 2021-07-07 ### ***** "Review" Excellent app and easy to use -- p greenwood, 2021-06-15 ### ***** "Excellent" I downloaded this app last year and it was great very handy, There was an issue with the software but the developers was extremely helpful and went out of their way to fix this issue, I’ve recently downloaded the updated version and can honestly say it’s gold excellent stuff -- Astect Gibbo, 2021-01-20 ### ****- "Great app but..." Love this app very handy when needing to remember figures,values etc. However since iOS 14 sadly does no longer display correctly on my iPhone xs which deems some of the functions unusable atm - hopefully a fix for this is in the pipeline?. -- Cj-iphone Xs, 2020-12-02 ### ***** "Electrician" Constantly improving and adding more information to the app -- Jungomeemop, 2020-10-23 ### ***** "Handy pocket guide" Great app!!! I have been using this app for a few years now and I can not fault it, it’s easy and convenient to use and rather than having to overthink and take you away from the everyday job it saves time. -- Ryan 'hamster' Hamdy, 2020-09-02 ### ***** "Very handy" All your applications are very useful, quick to operate. Keep up the great work Thanks -- Ivo008, 2020-05-28 ### ****- "Mr C Davie" Great App saves a lot of time highly recommendable App part of my tool kit -- cals pals, 2020-04-22 ### *---- "Pointless" Downloaded for values on a BSEN 60947-2 MCCB and it just comes up with check manufacturers specifications..!! So waste of money. -- staples71, 2020-04-03 ### ***** "Very handy" Works well for me. -- comedy explorer, 2018-06-28 ### ***-- "Good app values not amendment 3" Good app but doesn't appear to update as the values are not as amendment 3 in the yellow book. -- tellurian1, 2015-05-06 ### *---- "Pants!" App keeps freezing. Waste of cash -- Ted87h, 2013-07-09 ### ****- "Gaz Hanlon" Works well and very useful at times -- gazza/electrician, 2013-01-09 ### *---- "Would be a great app if it worked" Crashes most of the time , just brought and could not open for hours, once loaded wouldn't load any details I asked for. I'm a sparky and would love this app to work! -- JB Sparks, 2012-12-27 ### ***** "Thanks for update, now works great." Now works great on ios 6, thanks for the update. -- Sparky110, 2012-11-05 [View all Max Zs Values reviews and detailed analytics on AppTail](https://apptail.io/account/signup?utm_campaign=ai-crawl&utm_content=reviews) ## Max Zs Values Store Rankings | Chart | Country | Category | Rank | |-------|---------|----------|------| | Top Paid | United Kingdom | Reference | #10 | | Top Paid | Ireland | Reference | #151 | | Top Paid | United Kingdom | Overall | #208 | | Top Paid | Dominican Republic | Reference | #292 | | Top Paid | United Arab Emirates | Reference | #316 | | Top Paid | India | Reference | #320 | | Top Paid | Ecuador | Reference | #335 | ## Max Zs Values Discovered Keywords - max zs values ## Max Zs Values Available In - [United Kingdom](https://apptail.io/app/max-zs-values-Ynae/united-kingdom) - [Australia](https://apptail.io/app/max-zs-values-Ynae/australia) - [Belgium](https://apptail.io/app/max-zs-values-Ynae/belgium) - [Switzerland](https://apptail.io/app/max-zs-values-Ynae/switzerland) - [Colombia](https://apptail.io/app/max-zs-values-Ynae/colombia) - [Czechia](https://apptail.io/app/max-zs-values-Ynae/czechia) - [Denmark](https://apptail.io/app/max-zs-values-Ynae/denmark) - [Spain](https://apptail.io/app/max-zs-values-Ynae/spain) - [Hong Kong SAR China](https://apptail.io/app/max-zs-values-Ynae/hong-kong) - [Indonesia](https://apptail.io/app/max-zs-values-Ynae/indonesia) - [Ireland](https://apptail.io/app/max-zs-values-Ynae/ireland) - [Kuwait](https://apptail.io/app/max-zs-values-Ynae/kuwait) - [Luxembourg](https://apptail.io/app/max-zs-values-Ynae/luxembourg) - [Malaysia](https://apptail.io/app/max-zs-values-Ynae/malaysia) - [Nigeria](https://apptail.io/app/max-zs-values-Ynae/nigeria) - [Netherlands](https://apptail.io/app/max-zs-values-Ynae/netherlands) - [New Zealand](https://apptail.io/app/max-zs-values-Ynae/new-zealand) - [Russia](https://apptail.io/app/max-zs-values-Ynae/russia) - [Sweden](https://apptail.io/app/max-zs-values-Ynae/sweden) - [Singapore](https://apptail.io/app/max-zs-values-Ynae/singapore) - [Taiwan](https://apptail.io/app/max-zs-values-Ynae/taiwan) - [Ukraine](https://apptail.io/app/max-zs-values-Ynae/ukraine) - [United States](https://apptail.io/app/max-zs-values-Ynae/united-states) - [Uzbekistan](https://apptail.io/app/max-zs-values-Ynae/uzbekistan) - [Vietnam](https://apptail.io/app/max-zs-values-Ynae/vietnam) - [Argentina](https://apptail.io/app/max-zs-values-Ynae/argentina) - [South Africa](https://apptail.io/app/max-zs-values-Ynae/south-africa) --- ## About AppTail [AppTail](https://apptail.io) is a mobile app intelligence platform providing app analytics, ASO (App Store Optimization) tools, keyword tracking, competitor analysis, revenue estimates, and review monitoring for iOS App Store apps. 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