An uninterrupted power supply (UPS) is a backup power source that helps prevent disruptions to the continuous operation and service of data systems in the event of a power outage.

This article guides you through how to choose a suitable UPS and set it up.

1. Calculate the total wattage of all devices
2. Choose a UPS
3. Connect your Synology product to the UPS

1. Calculate the total wattage of all devices

Calculate the total wattage of all your devices. For example, assume the following devices require the use of a UPS device: a computer, a computer monitor, a Synology DS918+, and a network switch. The total wattage of these devices are as follows:

• Computer: 450 W
• Computer monitor: 20 W
• DS918+: 100 W
• Network switch: 80 W
• Total wattage: 650 W

2. Choose a UPS

For example, if the total wattage required for your devices is 650 W and the output power factor of a UPS is 70%, you should select a UPS with output power greater than 930 W.  Output power is calculated as follows:

Output power = Total wattage of your devices / Output power factor of a UPS

Therefore, following our example:

Output power required = 650 / 70% = 928.5

Please refer to the Synology Product Compatibility List to check which UPS is compatible with your Synology product.

Different manufacturers have different volt-ampere (VA) ratings based on the performance of their UPS. To determine the total power (W) that the UPS can support, we recommend consulting the manufacturer's product manual.

Additionally, you should also verify the battery capacity and available runtime of the UPS. Different UPS have varying battery capacities, which are crucial in determining how long your UPS will last in the event of a power outage.

3. Connect your Synology product to the UPS

After purchasing a UPS compatible with your Synology product, please connect the two products, then go to the DSM Control Panel > Hardware & Power  > UPS, and follow the steps below:

For DSM 6.2 and below:

1. Tick Enable UPS support.
2. Tick Time before DiskStation enters Safe Mode.
3. Select the length of time before the device enters Safe Mode. Enter a value in the field and select seconds, minutes, or hours from the drop-down menu.¹

For DSM 7.0 and above:

1. Tick Enable UPS support.
2. Select a UPS type from the drop-down menu.
3. Select a Time before DiskStation enters Safe Mode. You can select Until low battery or customize a a length of time before the device enters Safe Mode.

After the Synology product is successfully connected to the UPS and Safe Mode is enabled, in the event of a power outage, the Synology product will automatically enter Safe Mode when the UPS is low on power or the set time for entering Safe Mode has been reached.