ESI IVX C-Class Installation Manual page 14

Hardware overview/installation
is not unusual for these types of units to be able to regulate utility power, even when it drops to 27%
below or rises to 33% above normal, all without using their batteries.
From this point, UPSs can be further broken down by inverter types, which determine output. These are:
• Square wave.
• Modified sine wave (or quasi sine wave).
• Sine wave.
Most devices with wall-mounted chargers, such as cordless drills or screwdrivers, can behave erratically
— sometimes not allowing the charge circuit to engage at all — when operating with modified sine or
square wave inverters. Small wall-based transformer-style power supplies, similar to those ESI phone
systems use, can experience overheating problems with modified sine or square wave outputs, which
occur while some UPSs are operating in battery mode. This overheating could eventually cause
damage to the power supplies; and, in time, the damage could cause a spike through the phone system
— seriously damaging some of the static-sensitive components inside the casing.
While the true sine wave UPS output power curve smoothly increases to its peak, then smoothly
decreases (allowing connected loads and equipment to operate the same as they would from utility
supplied wall power), the modified sine wave and square wave UPS output power curve will shoot
straight up, level off at peak voltage and then drop straight down. Additionally troublesome is that the
modified sine wave sits at zero voltage for a short period during the transition to or from batteries —
which is the main difference between it and the square wave output of some UPS. Please note that this
short interval during which the modified sine wave UPS sits at zero voltage can directly affect the
transfer time of the UPS and could, theoretically, be enough to cause the phone equipment to reset or
even "freeze."
Though it is hard to predict exactly when different ESI systems will have problems with modified sine
wave or square waveform UPSs (meaning during a power failure event or the recovery from one), it's
fair to assume that a problem will eventually arise from the use of such UPSs. Therefore, ESI
recommends that only true sine wave output UPSs provide backup power to our phone systems
and equipment.
LED functions
The unit's various LEDs are designed to provide visual feedback as follows:
Power LED
The Power LED is located on the top-right side of the cabinet and is illuminated when power is being
applied to the system. This LED blinks periodically to indicate that the main processor is operational.
Memory Transfer LED
This LED is located inside the cabinet in the center of the main board. It serves as a diagnostic aid by
flashing as data is transferred to and from the Memory Module.
B.8
IVX C-Class with voice mail: Installation Manual