The current electrical system found on the SYSCO
site is an eclectic mix of redundant power systems built over a
100 year period. Over the decades, the overriding concern when installing
new services was to make sure that the up-grades did not jeopardize
on-going operation of the mill. Conversely, many old systems were
left in place, as the SYSCO engineers were unsure if their removal
would leave critical pieces of machinery without power. The result
is a large amount of surplus and/or redundant equipment, all of
which is owned and operated by SYSCO. The layout is shown on Figure
In a meeting held in January of 2001, Nova Scotia Power (NSP) made
known their intentions to NOT take over the electrical equipment
on the SYSCO site. Instead, new tenants and power users on the site
would need to be serviced individually from the existing NSP distribution
grid. The existing SYSCO power grid functions at a distribution
voltage of 2300 volts, the old industry standard which was sufficient
for the needs of the steel mill. NSP has recently finished costly
upgrades to its systems province wide to eliminate all 2300 volt
distribution and maintain a 12,500 volt distribution grid.
When it was in full production, the site used three main electrical
substations: North substation, South substation, and Substation
#1. Substation #1 formerly housed a 69 kV transformer that supplied
the necessary voltage to run the incinerator. When this transformer
failed, a suitable replacement could not be found. With the incinerator
not functioning, a smaller transformer was installed in its place
to maintain lights and heat in the SERL buildings. This transformer
will not support the incinerator. The north and south substations
have 50 MVA capacities, and are in very good condition. These two
substations are interconnected, meaning that either can supply power
to the entire site.
The Static Var substation is a smaller substation on site, and
was specifically de-signed to power the electric arc furnace. It
can be decommissioned when the furnace is sold. The No. 2 powerhouse
receives 23,000 volts and steps down to 6,600 and 2,300 volts, and
converts the AC power to DC for the use of the majority of the cranes.
It also supplies the 6,600 volt to the Sydney River potable &
process water pumping station.
It is possible to disconnect the Sydney River pumping station,
the administration building, and the gate and security buildings
from the internal system and feed them directly from the NSP grid,
thus enabling the decommissioning of the No. 2 powerhouse, although
the reconnection may trigger a re-evaluation of the fee structure
charged by NSP. The rectifiers and associated equipment can be removed
from No. 2 powerhouse and installed into a new electrical room with
a minimum size 20’x20’.
Required electrical upgrades to the site include a new electrical
line to the wharf, which is currently fed 2,300 volts from the north
substation. The anticipated cost of this upgrade is $50,000 to $100,000.