5
Current Requirements
The MTS-4 presents a dynamic load to the AC mains
which causes the amount of current to fluctuate between
quiet and loud operating levels. Since different types of
cables and circuit breakers heat up (and trip) at varying
rates, it is essential to understand the types of current
ratings and how they correspond to circuit breaker
and cable specifications.
The maximum continuous RMS current is the maximum
RMS current over a duration of at least 10 seconds. It is
used to calculate the temperature increase in cables,
which is used to select cables that conform to electrical
code standards. It is also used to select the rating for
slow-reacting thermal breakers.
The maximum burst RMS current is the maximum RMS
current over a one second duration. It is used to select
the rating for most magnetic breakers.
The maximum instantaneous peak current during burst
is used to select the rating for fast-reacting magnetic
breakers and to calculate the peak voltage drop in long
AC cables according to the formula
V
pk
drop
=
I
pk
x
R
total cable
Use the table below as a guide to select cables and circuit
breakers with appropriate ratings for your operating volt-
age.
s
g
n
i
t
a
R
t
n
e
r
r
u
C
4
-
S
T
M
V
5
1
1
V
0
3
2
V
0
0
1
S
M
R
s
u
o
u
n
i
t
n
o
C
.
x
a
M
A
4
1
S
M
R
A
7
S
M
R
A
6
1
S
M
R
S
M
R
t
s
r
u
B
.
x
a
M
A
6
2
S
M
R
A
3
1
S
M
R
A
0
3
S
M
R
t
s
r
u
B
g
n
i
r
u
D
k
a
e
P
.
x
a
M
A
2
2
K
A
E
P
A
8
1
K
A
E
P
A
2
4
K
A
E
P
The minimum electrical service amperage required by a
system of Meyer speakers is the sum of their maximum
continuous RMS
currents. We recommend allowing an
additional 30% above the minimum amperage to prevent
peak voltage drops at the service entry.
TROUBLESHOOTING NOTE:
In the unlikely case that
the circuit breakers trip (the white center buttons pop
out), do not reset the breakers! Contact Meyer Sound for
repair information.
Safety Issues
Pay close attention to these important electrical and
safety issues.
Use a power cord adapter to drive the MTS-4
from a standard 3-prong outlet (NEMA 5-15R;
125 V max).
earth
ground
chassis
ground
The MTS-4 requires a grounded outlet. Always
use a grounding adapter when connecting to
ungrounded outlets.
Do not use a ground-lifting adapter or cut the AC
cable ground pin.
Keep all liquids away from the MTS-4 to avoid hazards
from electrical shock.
Do not operate the unit if the power cables are frayed or
broken.
Tie-wrap anchors on the amplifier chassis provide strain
relief for the power and signal cables. Insert the plastic
tie-wraps through the anchors and wrap them around
the cables.
