UPS not charging on electricity but charge on Generator

Discussion in 'General Electronics Chat' started by walediscovery, Nov 23, 2015.

  1. walediscovery

    Thread Starter New Member

    Nov 23, 2015
    Good day everyone,

    Please my office 30KVA UPS will not charge on main supply (electricity). It only charge while on generator (plant).

    The batteries are not up to a year.

    Please what do you think is the issue.

  2. kubeek

    AAC Fanatic!

    Sep 20, 2005
    It could be that your wiring is not good enough to sustain the charging current.
    walediscovery likes this.
  3. walediscovery

    Thread Starter New Member

    Nov 23, 2015
    But the batteries get charged while on company generators. The issue is when you receive power via the power utility company.
  4. Dodgydave

    Distinguished Member

    Jun 22, 2012
    Have you measured the mains supply voltage from your office, and compared it with your generator?
    MrSoftware and walediscovery like this.
  5. alfacliff

    Well-Known Member

    Dec 13, 2013
    get a real electrician to check the wireing, it is probably wired up that way.
    walediscovery likes this.
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    Need wiring diagram showing how generator and mains are attached to UPS..
    Need to know UPS specifications
    Need to know voltage measurements for mains and generator output
    How do you know its not charging?

    As alfacliff stated an electrician should be able to look at it and find out whats wrong easily.
    walediscovery likes this.
  7. MrSoftware


    Oct 29, 2013
    Is this a problem that suddenly began when the system was working properly in the past? Did anything change just prior to this problem occurring?

    Check your utility line voltage. We had a problem with the line outside our building causing the voltage to sag, and our UPS's were running in boost mode (drawing more current to boost the voltage). Occasionally the voltage would drop low enough that they would trip to battery power, but they would run for extended time in this boost mode. I believe the batteries were not charging when running in this state. It's worth checking if yours is similar. Check the line voltage, and also check the UPS logs is possible, the UPS will likely log the events.
    walediscovery likes this.
  8. walediscovery

    Thread Starter New Member

    Nov 23, 2015
    Thanks all. Yes, the issue started this month. It has been working fine prior to this time.

    I will do as advised and revert