APC MX28B-1200 User Manual

Revision B 

MX28B-1200   PRODUCT MANUAL 

MX28B-1200/2400 

29 

 

The MX28B system control unit is delivered with pre-programmed parameter default settings.  
A complete listing and description of all system configuration parameters as well as displayable 
system status and information is provided in Section 6.  Read Section 6 to gain an understanding 
of and how to use the operational features provided by the MX28B dc power plant.  As a 
minimum, the following parameters should be verified and adjusted, if required, before 
connecting batteries or loads to the power plant: 

1)  Battery Float Voltage - default = -54.00V dc  (Check the manufacturer’s 

recommendation for the batteries being used in the system.) 

2)  Battery Maximum Recharge Rate - default = 50A.  (Bellcore specifications 

recommend a maximum charging rate of battery capacity (in Ampere-hours) divided by 
20 hours; check the manufacturer’s recommendation.) 

3) System Voltage - measurement 

≅ -54.00V dc  (This is a measurement by the system of 

the dc output bus voltage.) 

4) LVD Option - default = “Enable”  (If the MX28B does not have an LVD installed, this 

should be changed to “Disable”.) 

5) Rectifier Information - Check the rectifier information displays to verify that all 

rectifiers installed can be viewed on the control unit display and that no rectifier alarms 
are active. 

Section 6 provides location information for these parameters and how to make changes if 
required. 

To complete a full system power up, perform the following steps 

1) Turn OFF all the circuit breakers that supply ac power to the rectifiers in the MX28B dc 

power plant. 

2)  Turn on the external circuit breaker from the battery to the power plant. 

3)  Turn on all the circuit breakers that supply ac power to the rectifiers in the MX28B dc 

power plant.  

4)  Load circuit breakers and distribution fusses may now be turned on and inserted as 

required.