6
106 Bypass Switches
If your FERRUPS model does not have a power cord and plug, you should have a Best Power bypass switch.
The cabinet for these switches may be separate (external) or attached to the back of the UPS (internal).
The bypass switch has four positions (see Table 5 below). In the UPS or LINE positions, AC input power is
still connected to the input terminals inside the UPS once it is installed. To disconnect AC input power
during maintenance or service, turn the bypass switch to SERVICE. For Make-Before-Break switches, please
note that you must press the red button before you can change the switch position.
Table 5: Bypass Switch Positions
Bypass switches may be Make-Before-Break (MBB) or Break-Before-Make (BBM).
Make-Before-Break switches make a new connection before they break the present connection. For example, if
you turned the switch from “UPS” to “LINE,” the bypass switch would connect your protected equipment to AC
input power before disconnecting the equipment from UPS output power. Make-Before-Break switches are not
for use with 208 VAC.
Break-Before-Make switches break the present connection before they make a new one. If you turned a Break-
Before-Make switch from “UPS”to “LINE,” the switch would disconnect your protected equipment from UPS
output power before connecting the equipment to AC input power.
Bypass switches come in four models, and each model has its own ratings for current and voltage. Table 6 below
lists the ratings and weights for Best Power bypass switches.
Table 6: Bypass Switch Ratings and Weights
Switch Position Explanation
LINE
Connects the loads (protected equipment) directly to AC line input and disconnects UPS output. AC
line input is still connected to the UPS itself.
OFF
Disconnects the protected equipment from both UPS output power and AC input power.
SERVICE
UPS
Like the LINE position, SERVICE connects the loads (protected equipment) directly to AC line input
and disconnects UPS output. However, since SERVICE also disconnects AC input, this is the
appropriate switch position during UPS maintenance or repair.
Connects the UPS output to the protected equipment.
Bypass Switch Model
Ratings, Continuous
Weight (lbs/kg)
BPE12
(External Bypass Switch)
40A/300VAC (CSA)
50A/300VAC (UL, TÜV)
27 lbs. / 12.3 kg
BPE14
(External)
80A/300VAC
31 lbs. / 14.1 kg
Internal Bypass Switch for
2 kVA and 3 kVA Models
40A/300VAC (CSA)
50A/300VAC (UL, TÜV)
Internal Bypass Switch for
4.5, 6 and 7.5 kVA Models
80A/300VAC