Bulletin
Category:
ELECTRICITY
Document(s):
LMB-EG-07, S-E-06 and
Bulletin:
E-XX
Issue Date:
2013-XX-XX
Page:
1 of 3
Effective Date:
2013-XX-XX
E-30
Supersedes:
Policy on Demand Measurement Established Using a Demand Interval Length Other Than
the Programmed Demand Interval Length
1.0
Purpose
The purpose of this bulletin is to provide Measurement Canada’s (MC) policy on demand
measurements that are established using a demand interval length other than the programmed
demand interval length.
2.0
Scope
This bulletin applies to all electricity meters which are used to establish the basis of a charge for
demand in legal units of measure.
3.0
References
LMB-EG-07—Specifications for Approval of Type of Electricity Meters, Instrument Transformers
and Auxiliary Devices[link 1]
S-E-06—Specification for the Approval of Type of Electricity Meters and Auxiliary Devices –
Amendments to Measurement Canada Specification LMB-EG-07[link 2]
Bulletin E-30—Policy Decisions and Interpretations Related to Specification LMB-EG-07[link 3]
Category:
ELECTRICITY
Document(s):
LMB-EG-07, S-E-06 and
Bulletin:
E-XX
Issue Date:
2013-XX-XX
Page:
2 of 3
Effective Date:
2013-XX-XX
E-30
Supersedes:
4.0
Background
MC has recently discovered that the demand interval length of certain approved electricity meters
can be modified under certain operating conditions or events (e.g., when an over-the-air remote
adjustment is made to the real-time clock or during power down and power up, time-of-use rate
changes, activation and deactivation of certain meter modes, etc.). Under these conditions, the
demand interval length is temporarily changed such that the energy registered for the purpose of
establishing demand is gathered over an interval which may be less than 15 minutes in length.
This results in non-compliance with the approval requirement of clause 5.15.3 of specification SE-06, which prescribes that the demand interval be not less than 15 minutes.
MC considers the practical manifestation of this non-compliance to be important, as it affects
numerous meters in Canada. The Agency has issued an amendment to Bulletin E-30 to clarify
the intent of the above-mentioned approval requirement and its applicability to the meter. An
installation and use specification may be issued in the future to prescribe requirements for the
establishment of demand values outside an approved electricity meter in a manner that complies
with this policy.
The demand interval length is considered a type-specific legally relevant parameter and as such,
it cannot be modified under existing MC policies and requirements.
5.0
Policy
Manufacturers have reported that most existing meters have been designed with features which
mitigate the impact of a shortened demand interval length on registered demand values.
Therefore, as this will not disadvantage consumers, MC has decided to permit temporary
adjustments to demand intervals subject to the conditions listed below.
5.1
Where demand measurements are established using a demand interval length other than
the programmed interval, the demand registration will be deemed acceptable as follows:
(a) the meter discards any demand measurement which is established on the basis of
energy data accumulated over an interval which is either shorter or longer than the
programmed interval, or
(b) the energy data is accumulated over an interval of less than 15 minutes, however the
demand value is calculated using the energy data as if it was registered over the actual
programmed demand interval (typically 15 minutes).
5.2
In the case of meters that establish demand on the basis of sliding window algorithms,
the provisions of 5.1 shall apply to the subinterval. In addition, demand calculation for sliding
window demand shall be based on contiguous running time subinterval data. Demand
measurements subsequent to a power outage lasting greater than a complete subinterval shall be
determined as if the previous two subintervals contain no energy data.
Category:
ELECTRICITY
Document(s):
LMB-EG-07, S-E-06 and
Bulletin:
E-XX
Issue Date:
2013-XX-XX
Page:
3 of 3
Effective Date:
2013-XX-XX
E-30
Supersedes:
5.3
Manufacturers are responsible for identifying meters which have updateable clocks and
providing a statement of their level of compliance. They shall communicate to MC’s laboratory
any existing products that are not compliant with the requirements of this bulletin.
5.4
Meter owners will not be required to make changes to approved and verified meters
already in service as of the effective date of this bulletin, provided the meters incorporate the
design characteristics described in section 5. MC has concluded that, given the low risk to
electricity consumers, removal of such meters is not warranted.
6.0
Additional Information
For additional information regarding this bulletin, please contact the Senior Program Officer
responsible for electricity measurement. For more information regarding Measurement Canada
and its programs, visit our website[link 4]
Guy Dacquay
Manager - Utility Metering Division
[link 1] http://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/lm00168.html
[link 2] http://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/lm00174.html
[link 3] http://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/lm00033.html
[link 4] http://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/Home