MidNite Solar MNBE-A User manual

Small Battery Box Instructions
Model MNBE-A
Rev: A Page 1 of 6
14000 Burn Rd
Arlington, WA 98223
USA
Ph [phone]
www.midnitesolar.com
IMPORTANT SAFETY INSTRUCTIONS
SAVE THESE INSTRUCTIONS - These instructions contain important safety and operating instructions for
the MidNite Solar Battery Enclosure Size A for residential and commercial applications.
If you do not fully understand any of the concepts, terminology, or hazards outlined in these instructions,
please refer installation to a qualified dealer, electrician or installer. These instructions are not meant to be a
complete explanation of a renewable energy system.
GENERAL PRECAUTIONS
WORKING WITH OR IN THE VICINITY OF A LEAD ACID BATTERY, SEALED OR VENTED IS
DANGEROUS. VENTED BATTERIES GENERATE EXPLOSIVE GASES DURING NORMAL
OPERATION. FOR THIS REASON, IT IS VERY IMPORTANT THAT BEFORE SERVICING
EQUIPMENT IN THE VICINITY OF LEAD-ACID BATTERIES YOU REVIEW AND FOLLOW THESE
INSTRUCTIONS CAREFULLY.
If service or repair should become necessary, contact MidNite Solar Inc. Improper servicing may result in a
risk of shock, fire or explosion. To reduce these risks, disconnect all wiring before attempting any
The MidNite MNBE-A is designed for those applications where a small battery bank is required.
This enclosure is listed for indoor use. It can hold two group 31 batteries per shelf end to end or three side by
side, or one 8D per shelf. Group 31 batteries are typically 105 amp hours at 12v.

Small Battery Box Instructions
Rev: A Page 2 of 6
maintenance or cleaning. Turning off the inverter will not reduce these risks. Solar modules produce power
when exposed to light. When it is not possible to disconnect the power coming from the Photovoltaics by an
external means such as a combiner, cover the modules with an opaque material before servicing any
connected equipment.
Never attempt to charge a frozen battery.
When it is necessary to remove a battery, make sure that the battery bank disconnect breaker is in the off
position and that the PV breakers, grid breakers and any other sources of power to the inverter are in the off
position. Then remove the negative terminal from the battery first.
To reduce risk of battery explosion follow these instructions and those published by the battery manufacturer
as well as the manufacturer of any additional equipment used in the vicinity of the batteries. Before installing
the battery enclosure, read all instructions and cautionary markings in or on any connected electrical
equipment.
Avoid producing sparks in the vicinity of the batteries when using vented batteries. Provide ventilation to
clear the area of explosive gases. Sealed AGM and Gel batteries do not under normal conditions create
explosive gases. Be especially cautious when using metal tools. Dropping a metal tool onto batteries can short
circuit them. The resulting spark can lead to personal injury or damage to the equipment. Provide ventilation
to outdoors from the battery compartment when installing vented batteries such as golf cart T-105 batteries.
The addition of a spill tray is also a good idea.
Clean all battery terminals. Very high currents are drawn from the batteries; even a small amount of electrical
resistance can result in overheating, poor performance, premature failure or even fire.
Have plenty of fresh water and soap nearby in case battery acid contacts skin, clothing or eyes. Wear
complete eye and clothing protection. Always avoid touching eyes while working near batteries. If battery
acid or battery terminal corrosion contacts skin or clothing, wash immediately with soap and water. If acid
enters the eyes, immediately flood with cool running water for at least 15 minutes and get medical attention
immediately. Baking soda neutralizes battery acid electrolyte. Keep a supply near the batteries.
Do not work alone. Someone should be in the range of your voice or close enough to come to your aid when
you work with or near electrical equipment.
Remove rings, bracelets, necklaces, watches etc. when working with batteries, photovoltaic modules or other
electrical equipment. Power from an illuminated photovoltaic array makes a very effective arc welder with
dire consequences if one of the welded pieces is on your person.
To reduce the risk of injury, connect only deep cycle lead acid type rechargeable batteries. Other types of
batteries may leak or burst, causing personal injury or damage.

Small Battery Box Instructions
Rev: A Page 3 of 6
#6 Flathead
(15)
3 s
p
are
#10 Hex head
(18)
Loc
k
#10 Flathead (8) Hole plug
Hinge
Badge
Key
Handle
Lock BodyWasherNutTab
Screw
Hardware Identification
Some screws enlarged
to show detail

Small Battery Box Instructions
Rev: A Page 4 of 6
Step 4
Attach hinges and door using twelve #6 X 3/8” Flat head Philips
sheet metal screws.
Hint: attach the hinges to enclosure and then attach the door
afterwards.
If mounting the enclosure outdoors, the addition of a thin weather
strip around the door flanges may be required.
It is recommended to perform the assembly on a flat surface. You will require a #2 Philips screw driver
and a 5/16” wrench to tighten screws, as well as a slotted screw driver and hammer to remove Knockouts.
Assembly:
Step 2
Attach back using six # 10 X 3/8 Hex Head sheet
metal screws. Note: the front door and back panel are
identical. Fill the unused lock hole with the snap in
plug provided.
Step 1
Attach the two shelves to the sides using eight #10 X
3/8” Hex Head Sheet metal screws from the sides and
eight #10 Flat head Philips sheet metal screws front and
back. See image below.
#10 Hex head sheet metal screw.
6 Places
Step 3
Secure top to sides using four #10 X 3/8” Hex Head sheet
metal screws. The large knockout goes towards the rear of the
battery box. The MNBE-A is listed for use indoors, however if
the installation is to be made outside, the inside corner seams
of the top should be sealed up using 100% silicone sealant
available from your local hardware store. Do this prior to
installing the top cover.

Small Battery Box Instructions
Rev: A Page 5 of 6
Step 5
Install lock. The lock will require disassembly in
order to feed it through the hole and slot. The
handle, lock body and washer go in from the front.
Position the lock body such that the cutout faces
towards the upper left as viewed from the front.
Secure lock body with the nut provided from the
back. Position the tab on the back of the lock and
tighten screw.
Note: Unit is locked when the tab is up (behind
shelf
)
.
Lock viewed from inside Lock viewed from outside
Optional DC Disconnect installation.
Many Jurisdictions are beginning to require
DC disconnects as part of the installation.
A double knockout is provided on the side
of the battery box to satisfy this
requirement.
Important! You must use sealed AGM or
Gel batteries when installing a circuit
breaker / DC disconnect in the cabinet.
Circuit breakers make sparks and vented
batteries cannot be in the same cabinet with
any device that makes arcs and sparks. The
circuit breaker must be installed in the
positive leg. Do not install in the negative
leg.
Battery box with no
breaker. Battery box with 125 amp
DC breaker. Remove only
the inner knockout
Battery box with 250 amp DC
breaker and optional protector.
Remove entire knockout.
You may want to bolt the enclosure down using the .265” diameter holes on the bottom side flanges. You can
additionally drill holes through the back panel and bolt to a wall behind the enclosure to help make it earthquake
proof.
If two enclosures are required, they can easily be stacked horizontally. There are two sets of 2” knockouts on each
end plate that will accommodate running cables through a 6” long 2” diameter nipple. If stacking vertical, place a
¾” thick piece of wood inside the top cover of the lower enclosure on each end for added strength. This will keep
the lower cabinet from being crushed from the added weight. The upper enclosure should be bolted through the
back to a wall.
Slots are provided at the ends of the shelves for strapping batteries to the shelves. You will need to run strapping
for the bottom shelf prior to final positioning of the enclosure. Strapping is not supplied as part of the MNBE-A
kit.
The enclosure is set up to use sealed batteries as is. If installing flooded batteries, you may need to add venting
and spill trays. These items are not supplied by MidNite Solar.
Always use caution when hooking up batteries. They can be very dangerous. Do not wear rings or watches. Pay
close attention to the order of cable installation. For instance if four 12V batteries are to be configured as a 24
volt bank, the batteries will be more safe to work around if the series connecting jumpers are installed after all
other connections have been made.
Note: Battery banks below 50 volts are not required to be grounded per the NEC.

Small Battery Box Instructions
Rev: A Page 6 of 6
175A
12V BATTERY
25K
AIC POSITIVE NEGATIVE
BATTERY BATTERY
SHUNT
INVERTER
48 VOLT
12V BATTERY
12V BATTERY12V BATTERY
175A
6V BATTERY
25K
AIC POSITIVE NEGATIVE
BATTERY BATTERY
SHUNT
INVERTER
24 VOLT
6V BATTERY
6V BATTERY6V BATTERY
175A
12V BATTERY12V BATTERY
12V BATTERY12V BATTERY
25K
AIC
POSITIVE NEGATIVE
BATTERY BATTERY
SHUNT
INVERTER
24 VOLT
Common battery wiring configurations.
24 Volt system with four 12 volt batteries.
This is a series parallel setup with two
batteries in series paralleled with two more
batteries in series.
48 Volt system with 4 – 12 volt batteries
This setup has four 12 volt batteries in
series to provide 48 volts.
24 Volt system with 4 – 6 volt batteries
This setup has four 6 volt batteries in
series to provide 24 volts.