Contact Information and Technical Support

Frequently Asked Questions

To help you quickly find an answer to a question relating to FormFill or CableCalc we have put together a list of the questions we are asked most often. If you cannot find the answer to your question here then please get in touch with us.

All Castline software downloads, updates and support files are provided only through official Castline websites and customer areas.

Licencing and account questions

• My program says it has expired but I have a current support or licence subscription?
This is often caused by incorrect details being entered or a change of address. Email support@castlinesystems.co.uk with your details and you will be emailed instructions on how to update or correct your registration details.

• What are “extra users” and do I need them?
Extra users allow you to use Castline software on more than one computer or on more than three mobile devices running the FormFill app. A standard licence includes use on one desktop/laptop and up to three mobile devices. If your team needs access beyond this, you’ll need to purchase extra users.

You may need extra users if:
• You want to run the software on multiple desktop or laptop computers.
• More than three mobile devices (e.g. engineers’ phones/tablets) need access to the FormFill app.
• Several staff members need to work independently on their own devices.

Example 1: You use Castline software on one office computer but have five engineers using the FormFill app. Because the licence includes three mobile devices, you would need two extra users.

Example 2: You have two engineers, each using their own laptop. Since the licence covers only one computer, you would need one extra user.

If you're unsure how many users your setup requires, our team is happy to help you choose the right configuration.

Downloads, updates and authenticity

• How can I check that my download is genuine?
All Castline installers are only distributed through official Castline domains and the customer area. Before opening any file, check that:
• the website address is a Castline domain,
• the installer publisher is Castline Systems,
• the download was started from your customer area or in-software update prompt.

• Where do software updates come from?
All updates are delivered directly from Castline Systems through the in-software updater or your official customer area. We do not distribute updates through third-party download websites.

• How can I check that I am running the latest version?
If you have a current licence or support subscription, the software will automatically notify you when an update is available. You can also manually check by selecting Internet → Check for Updates from within the software. Updates are only delivered through official Castline update servers.

• My browser warns that the installer may be harmful
Modern browsers and Windows security features may occasionally display a warning when downloading desktop software installers. This is most common after a new version release.

Before continuing, please confirm:
• The file was downloaded from your official Castline customer area
• The download link starts with https://castlinesystems.co.uk or your official download domain
• The installer publisher is shown as Castline Systems
Once these checks are confirmed, you can continue with the steps below.
Microsoft Edge

1. Start the download from your Castline customer area.

2. If Edge shows a warning, open the download options menu using the three dots.

3. Select the option to keep the verified Castline installer.

4. Review the file details and confirm the source before proceeding.

5. Open the downloaded file to begin installation.

Chrome / Windows SmartScreen
1. Download the installer from the official Castline customer area.

2. If Windows SmartScreen appears, choose More info.

3. Confirm the publisher is Castline Systems.

4. Once verified, continue with the installation using the Windows prompt.

Installation and permissions

• Do I need administrator access to install the software?
In most cases yes. Installing desktop software and PDF printer drivers usually requires Windows administrator permission. If you are on a managed company PC, your IT team may need to approve the installation.

• The program comes up with a box saying that it needs permission when trying to install.
This is a standard Windows security prompt shown when installing desktop software. Before allowing the installation, please confirm that the installer was downloaded from an official Castline page and that the publisher is shown as Castline Systems. Once confirmed, you can allow the installation to proceed.

Safe download and installation check

Castline software installers and support files are only provided through official Castline websites and download locations. Before opening any installer or driver file, please confirm that:

• the file was downloaded from an official Castline page or customer area,
• the website address is a Castline domain, and
• the installer publisher is shown as Castline Systems where Windows displays publisher information.

If these details match, you can continue with the download or installation steps below.

Printing and PDF issues

• My PDF print-outs are getting cut off the bottom or side.
This can happen after a Windows update whereby the default paper size gets changed from A4 to Letter. Go to Printers & Scanners in Windows Settings and select the Castline Printer. Select Printer Preferences or Properties and set the paper size to A4.

• The Castline printer is stuck as my default printer and I can't seem to change it.
This is caused by a setting in Windows printers and scanners to automatically set the default printer. Go to the Printers & Scanners in Windows Settings and turn-off the setting labelled Let Windows manage my default printer. Then set your desired printer to the default by clicking on it and selecting the button Set as default.

• When printing a PDF from Adobe Reader to my printer, some information is missing or in yellow.
Make sure you do not select the option for 'Save ink/toner', as this causes some information not to be printed.

FormFill Questions

• BS7671:2018 Amendment 3 was released on the 31st July 2024, why do my certificates still say BS7671:2018 AMD 2:2022 at the bottom?
While BS7671:2018 was updated to AMD3 last year, there were no changes to the forms as a result (the update was only to introduce bidirectional and unidirectional devices). AMD3 is only an addendum and as a result the forms are still based on the model forms in BS7671:2018 AMD 2 (2022) which hasn’t been reprinted to include amendment 3.

Where applicable there is a field on the certificates for the BS7671 Amended to date, where you would put ‘2024’.

• I am a member of the NICEIC, do I have to use their certificates or can I use FormFill to create them?
You can use any certificates that you like providing that they comply with BS7671. FormFill certificates comply with BS7671

• How do I add a signature?
To add your signature to the software, you must have access to and know how to use a scanner, or have a digital copy of your signature already stored on your computer. When scanning in your signature it is important that it is scanned in true black and white (1 bit) colour and saved as either a Bitmap (.BMP) file, PNG (.PNG) file or a JPEG (.JPG) file. We recommend that you use a good quality black ink pen that leaves an even trail of ink on the paper for best results. Biro or roller-ball pens tend to produce poorer results. Once you have scanned your signature into the computer using whatever software was supplied with your scanner, you must store the image in the default signatures folder, usually located inside your local Castline FormFill data folder.

To open the signatures section, select the ‘Set Defaults’ tab from the bottom of the screen, then click on the entry for ‘Digital Signatures’ on the left hand side. To add a new signature first click the ‘Get New Signature’ button. A screen will appear asking you to select the name of the file containing your signature. Click on your signature file from the list and click the ‘OK’ button.

The signature should now appear in in the box on the right. Enter a name and position to relate to this signature and click ‘Add to list’. The signature will now appear in the list and you will be able to select it from the quick entry menu when filling out certificates.

You can also ‘write’ a signature using the mouse (or a stylus if using a touch screen). To do so, click the ‘Write a New Signature’ button, ‘Draw’ your signature using the mouse, then click ‘OK’. Type in the name of the person whose signature it is when prompted and click ‘OK’. Select a position from the drop down list, or type one in, then click ‘OK’. The signature will be automatically added to the list for re-use. We only recommend drawing your signature with the mouse as a last resort as signatures created in this fashion are generally not of the best quality. This facility works very well however if you use the software on a touch screen tablet or PC, with a stylus.

• How do I change the colours on the custom certificate printouts?
Select 'Customise' and then 'colours' from the menu at the top of the screen, and select the colours you want from the Windows palette.

• I have my own logo already as a picture, how do I add it onto the custom printed forms?
Save your logo as a PNG image named logo.png inside your local FormFill data folder. In most installations this is the main Castline FormFill folder, though the exact location may vary by version.

• When I print a certificate all I get is a blank page or a message from Adobe Reader saying that the file cannot be found.
This usually happens on 64-bit versions of Windows which require a separate driver. Press F1 with the program open to view the manual and instructions for installing the drivers are on page 76.

• When I select a protective device on a 30mA RCD protected circuit, the maximum permitted Zs comes up as 1666 ohms instead of the devices Zs.
On TT supplies and also for final circuits of 32A and under on TN-C-S systems, it is permissible to use the maximum permitted Zs of the RCD where the RCD is in place for ADS. See regulation 411.4.7 on page 58 of BS7671 AMD3 for more information. You can also force FormFill to use the fuse/breaker Zs by unchecking the box labelled 'Use RCD Zs for final circuits' when selecting the protective device.

• The values of maximum Zs used by the program do not match those in the on-site guide or the 'green card' that I have.
These values on these cards are often adjusted by a rule of thumb, to 80% of the values in BS7671 to account for the fact that the circuit/fuse is not at operating temperature when tested. The value required on the forms is the value from BS7671 and the programs validation will warn you if your tested Zs exceeds 80% of the maximum Zs.

CableCalc Questions

• CableCalc isn't allowing me the option of selecting a 3 phase supply. The option is there but greyed out, how do I enable it?
The user defaults define the type of supply available for quick calculations. If you select the 'Set Defaults' button on the right side of the Supply tab, you should be able to set the default supply to 3 phase under the 'System' section. Don't forget to enter an appropriate Ze for a 3 phase supply under the 'Voltage' section as well.

• Why does CableCalc tell me I have no internet connection when I do, or gives an error establishing a connection to SQL Server?
This issue can occur due to your system setup. If your antivirus software blocks the program's access to the internet, CableCalc may not detect the connection. Alternatively, if the SQL port is blocked by your firewall, you may receive an error when trying to connect to the SQL Server.

Your IT department will need to ensure that CableCalc can connect to outgoing port 1433 (SQL) on castlinesystems.co.uk. Additionally, both https://castlinesystems.co.uk and https://secure.castlinesystems.co.uk should be added to your firewall or proxy server exceptions list.

• I am using CableCalc to calculate a circuit protected by an MCCB but whatever I do the circuit 'fails' on disconnection time and device impedance. It makes no difference what size of cable I use or what circuit protective conductor (cpc) I add to the circuit.
Check that the source impedance Ze for the installation is correct. The quoted electricity supply authorities typical maximum impedance values (0.35 ohms) are unlikely to be accurate in situations where an MCCB is used. If you can go to site and measure the Ze then your calculations will be much more accurate. MCCB's are also often equipped with an adjustable magnetic trip setting. Lowering the magnetic trip setting / device multiplier will increase the maximum permitted Zs, however you still need to be sure that you can achieve discrimination with up and downstream devices.

• How many CPC's can I include in a calculation when sizing a cable?
If the cable has a sheath or armouring then that may be used for the calculation together with options for using an internal core and/or a separate earth-wire (either automatically sized or selected). Trunking or conduit can also be selected as a CPC when appropriate.

• What happens if the maximum size of cable is exceeded when I am trying to calculate a cable size?
The program will attempt to meet the criteria for the calculation by selecting 2 cables in parallel, If this fails it will try it with 3 cables in parallel and so on up to a maximum of 20 cables.

• I have designed a project with twelve distribution boards feeding more than 300 circuits and now the architects have repositioned the main transformer. This has completely changed all of the main incoming figures, voltage, Ze, etc.
Simply input the revised source details and then click on the 'Calculate all' button. The whole system will be recalculated using the updated supply figures, and within a few minutes all of the circuits in the project will have been recalculated.