Alpha Vision Tech MPS48-7M technical manual Theory of Operation, Backhaul

2.0 Theory of Operation

The FlexNet MPS48-7M multipurpose power supply provides filtered 50W output power for a typical 48V telecom bus during normal line operation. During line disruptions, the MPS48-7M supplies uninterrupted output power of 50W directly from a string of four 12V batteries.

Metal oxide varistor (MOV) technology provides line voltage surge suppression in the event of line cross or power spikes. An electromagnetic filter conditions line voltage, enabling the power supply to operate in compliance with FCC Class A standards. The AC-to-DC converter feeds power to the primary winding of a high-frequency isolation transformer. The resulting DC output, at the secondary of the transformer, provides power to the load and charges the 48V string batteries, keeping them fully charged in preparation for a line disruption. MPS48-7M battery temperature compensation range is from -0ºC to 40ºC. A battery heater mat option extends battery life in cold environments. Maximum output voltage of 56Vdc.

The power module provides over-current, over-voltage, and short-circuit protection. After the fault is cleared, the power module automatically resumes power to the load. The control logic circuitry provides a LVD (low battery voltage disconnect), detects the presence (or absence) of batteries, performs periodic battery testing, and communicates status locally with LED status indicators.

Preconnectorized cables of varying lengths provide reliable and efficient field installation. Ethernet, 48Vdc power (with return), and RS232 interface are supported on the preconnectorized cables.

The MPS housing is constructed of weather resistant powder coated aluminum. The enclosure can be pole or wall-mounted.

AC service is routed into the bottom of the enclosure through a 1/2" Electrical Metallic Tubing (EMT) knockout located in the bottom center of the enclosure. The data and power cables are routed through a provided 3-hole strain relief fitting. Additional 1/2" and 3/4" knockouts are provided at the back, bottom, and sides of the enclosure.

The MPS48-7M interface module includes:

•An RJ11/RJ45 pair of connections support a mesh router. The RJ11 includes the RS232 connection to the router. The RJ45 provides an Ethernet connection between the router and 48VDC power (and return).

•An RJ45 for connection to a remote router or modem (Ethernet backhaul).

•An RJ11 Craft Port connection providing an RS232 connection to the mesh router for network management information.

•A 48Vdc terminal block for an auxiliary piece of equipment (e.g. a camera).

Aux		Radio,		Ethernet	Radio, Serial		Local Craft
		Power		Backhaul
Terminal Block		RJ45		RJ45		RJ11		RJ11
Pin	Pin		Pin		Pin		Pin
1 +48Vdc	1 Data		1	Data Pair 1	1	NC	1	NC
	Pair 1
2 Return	2 Data		2	Data Pair 1	2	Radio TX	2	Local RX
	Pair 1
	3	Data	3	Data Pair 2	3	Return	3	Return
	Pair 2
	4	+Vdc	4	NC	4	Radio RX	4	Local TX
	5	+Vdc	5	NC	5	NC	5 NC
	6	Data	6	Data Pair 2	6	NC	6	NC
	Pair 2
	7	- Vdc	7	NC
	8	- Vdc	8	NC

Table 2-1, Network Connections

021-511-B4-002, Rev. B 11